diff --git a/test/test_option_callback.py b/test/test_option_callback.py
index 53b896f..967f10c 100644
--- a/test/test_option_callback.py
+++ b/test/test_option_callback.py
@@ -1240,7 +1240,6 @@ def test_calc_value_condition():
 
 
 def test_calc_value_allow_none():
-    from tiramisu import calc_value, StrOption, OptionDescription, Config, Params, ParamOption, ParamValue
     val1 = StrOption('val1', "", 'val1')
     val2 = StrOption('val2', "")
     val3 = StrOption('val3', "", multi=True, callback=calc_value, callback_params=Params((ParamOption(val1), ParamOption(val2)), multi=ParamValue(True), allow_none=ParamValue(True)))
@@ -1250,7 +1249,6 @@ def test_calc_value_allow_none():
 
 
 def test_calc_value_remove_duplicate():
-    from tiramisu import calc_value, StrOption, OptionDescription, Config, Params, ParamOption, ParamValue
     val1 = StrOption('val1', "", 'val1')
     val2 = StrOption('val2', "", 'val1')
     val3 = StrOption('val3', "", multi=True, callback=calc_value, callback_params=Params((ParamOption(val1), ParamOption(val2)), multi=ParamValue(True), remove_duplicate_value=ParamValue(True)))
@@ -1260,7 +1258,6 @@ def test_calc_value_remove_duplicate():
 
 
 def test_calc_value_join():
-    from tiramisu import calc_value, StrOption, OptionDescription, Config, Params, ParamOption, ParamValue
     val1 = StrOption('val1', "", 'val1')
     val2 = StrOption('val2', "", 'val2')
     val3 = StrOption('val3', "", callback=calc_value, callback_params=Params((ParamOption(val1), ParamOption(val2)), join=ParamValue('.')))
@@ -1270,7 +1267,6 @@ def test_calc_value_join():
 
 
 def test_calc_value_min():
-    from tiramisu import calc_value, StrOption, OptionDescription, Config, Params, ParamOption, ParamValue
     val1 = StrOption('val1', "", 'val1')
     val2 = StrOption('val2', "", 'val2')
     val3 = StrOption('val3', "", 'val3')
@@ -1284,7 +1280,6 @@ def test_calc_value_min():
 
 
 def test_calc_value_add():
-    from tiramisu import calc_value, IntOption, OptionDescription, Config, Params, ParamOption, ParamValue
     val1 = IntOption('val1', "", 1)
     val2 = IntOption('val2', "", 2)
     val3 = IntOption('val3', "", callback=calc_value, callback_params=Params((ParamOption(val1), ParamOption(val2)), operator=ParamValue('add')))
diff --git a/test/test_requires.py b/test/test_requires.py
index d5124d4..45f9350 100644
--- a/test/test_requires.py
+++ b/test/test_requires.py
@@ -8,7 +8,7 @@ from tiramisu.setting import groups
 from tiramisu import setting
 setting.expires_time = 1
 from tiramisu import IPOption, OptionDescription, BoolOption, IntOption, StrOption, \
-                     Leadership, Config
+                     Leadership, Config, calc_value, Params, ParamOption
 from tiramisu.error import PropertiesOptionError, RequirementError
 from py.test import raises
 from tiramisu.storage import list_sessions, delete_session
@@ -65,6 +65,27 @@ def test_requires():
     api.option('ip_address_service').value.get()
 
 
+def test_requires_callback():
+    a = BoolOption('activate_service', '', True)
+    b = IPOption('ip_address_service', '',
+                 requires=[{'callback': calc_value, 'callback_params': Params(ParamOption(a)), 'expected': False, 'action': 'disabled'}])
+    od = OptionDescription('service', '', [a, b])
+    api = Config(od)
+    api.property.read_write()
+    assert not api.option('activate_service').option.requires()
+    assert api.option('ip_address_service').option.requires()
+    api.option('ip_address_service').value.get()
+    api.option('activate_service').value.set(False)
+    props = []
+    try:
+        api.option('ip_address_service').value.get()
+    except PropertiesOptionError as err:
+        props = err.proptype
+    assert frozenset(props) == frozenset(['disabled'])
+    api.option('activate_service').value.set(True)
+    api.option('ip_address_service').value.get()
+
+
 def test_requires_inverse():
     a = BoolOption('activate_service', '', True)
     b = IPOption('ip_address_service', '',
@@ -179,6 +200,44 @@ def test_requires_same_action():
     assert frozenset(props) == frozenset(['disabled'])
 
 
+def test_requires_same_action_callback():
+    activate_service = BoolOption('activate_service', '', True)
+    activate_service_web = BoolOption('activate_service_web', '', True,
+                                      requires=[{'callback': calc_value, 'callback_params': Params(ParamOption(activate_service)), 'expected': False,
+                                                 'action': 'new'}])
+
+    ip_address_service_web = IPOption('ip_address_service_web', '',
+                                      requires=[{'option': activate_service_web, 'expected': False,
+                                                 'action': 'disabled', 'inverse': False,
+                                                 'transitive': True, 'same_action': False}])
+    od1 = OptionDescription('service', '', [activate_service, activate_service_web, ip_address_service_web])
+    api = Config(od1)
+    api.property.read_write()
+    api.property.add('new')
+    api.option('activate_service').value.get()
+    api.option('activate_service_web').value.get()
+    api.option('ip_address_service_web').value.get()
+    api.option('activate_service').value.set(False)
+    #
+    props = []
+    try:
+        api.option('activate_service_web').value.get()
+    except PropertiesOptionError as err:
+        props = err.proptype
+    assert frozenset(props) == frozenset(['new'])
+    #
+    props = []
+    try:
+        api.option('ip_address_service_web').value.get()
+    except PropertiesOptionError as err:
+        props = err.proptype
+        submsg = '"disabled" (' + _('the calculated value is {0}').format('"False"') + ')'
+        assert str(err) == str(_('cannot access to {0} "{1}" because has {2} {3}').format('option', 'ip_address_service_web', 'property', submsg))
+        #access to cache
+        assert str(err) == str(_('cannot access to {0} "{1}" because has {2} {3}').format('option', 'ip_address_service_web', 'property', submsg))
+    assert frozenset(props) == frozenset(['disabled'])
+
+
 def test_multiple_requires():
     a = StrOption('activate_service', '')
     b = IPOption('ip_address_service', '',
@@ -326,6 +385,36 @@ def test_requires_transitive():
     assert frozenset(props) == frozenset(['disabled'])
 
 
+def test_requires_transitive_callback():
+    a = BoolOption('activate_service', '', True)
+    b = BoolOption('activate_service_web', '', True,
+                   requires=[{'callback': calc_value, 'callback_params': Params(ParamOption(a)), 'expected': False, 'action': 'disabled'}])
+
+    d = IPOption('ip_address_service_web', '',
+                 requires=[{'callback': calc_value, 'callback_params': Params(ParamOption(b)), 'expected': False, 'action': 'disabled'}])
+    od = OptionDescription('service', '', [a, b, d])
+    api = Config(od)
+    api.property.read_write()
+    api.option('activate_service').value.get()
+    api.option('activate_service_web').value.get()
+    api.option('ip_address_service_web').value.get()
+    api.option('activate_service').value.set(False)
+    #
+    props = []
+    try:
+        api.option('activate_service_web').value.get()
+    except PropertiesOptionError as err:
+        props = err.proptype
+    assert frozenset(props) == frozenset(['disabled'])
+    #
+    props = []
+    try:
+        api.option('ip_address_service_web').value.get()
+    except PropertiesOptionError as err:
+        props = err.proptype
+    assert frozenset(props) == frozenset(['disabled'])
+
+
 def test_requires_transitive_unrestraint():
     a = BoolOption('activate_service', '', True)
     b = BoolOption('activate_service_web', '', True,
@@ -589,6 +678,46 @@ def test_requires_multi_disabled():
     assert frozenset(props) == frozenset(['disabled'])
 
 
+def test_requires_multi_disabled_callback():
+    a = BoolOption('activate_service', '')
+    b = IntOption('num_service', '')
+    c = IPOption('ip_address_service', '',
+                 requires=[{'callback': calc_value, 'callback_params': Params(ParamOption(a)), 'expected': True, 'action': 'disabled'},
+                           {'callback': calc_value, 'callback_params': Params(ParamOption(b)), 'expected': 1, 'action': 'disabled'}])
+    od = OptionDescription('service', '', [a, b, c])
+    api = Config(od)
+    api.property.read_write()
+
+    api.option('ip_address_service').value.get()
+
+    api.option('activate_service').value.set(True)
+    props = []
+    try:
+        api.option('ip_address_service').value.get()
+    except PropertiesOptionError as err:
+        props = err.proptype
+    assert frozenset(props) == frozenset(['disabled'])
+
+    api.option('activate_service').value.set(False)
+    api.option('ip_address_service').value.get()
+
+    api.option('num_service').value.set(1)
+    props = []
+    try:
+        api.option('ip_address_service').value.get()
+    except PropertiesOptionError as err:
+        props = err.proptype
+    assert frozenset(props) == frozenset(['disabled'])
+
+    api.option('activate_service').value.set(True)
+    props = []
+    try:
+        api.option('ip_address_service').value.get()
+    except PropertiesOptionError as err:
+        props = err.proptype
+    assert frozenset(props) == frozenset(['disabled'])
+
+
 def test_requires_multi_disabled_new_format():
     a = BoolOption('activate_service', '')
     b = IntOption('num_service', '')
@@ -1006,6 +1135,56 @@ def test_leadership_requires():
     del ret['ip_admin_eth0.netmask_admin_eth0']
 
 
+def test_leadership_requires_callback():
+    ip_admin_eth0 = StrOption('ip_admin_eth0', "ip réseau autorisé", multi=True)
+    netmask_admin_eth0 = StrOption('netmask_admin_eth0', "masque du sous-réseau", multi=True,
+                                   requires=[{'callback': calc_value, 'callback_params': Params(ParamOption(ip_admin_eth0)), 'expected': '192.168.1.1', 'action': 'disabled'}])
+    interface1 = Leadership('ip_admin_eth0', '', [ip_admin_eth0, netmask_admin_eth0])
+    maconfig = OptionDescription('toto', '', [interface1])
+    api = Config(maconfig)
+    api.property.read_write()
+    assert api.option('ip_admin_eth0.ip_admin_eth0').value.get() == []
+    api.option('ip_admin_eth0.ip_admin_eth0').value.set(['192.168.1.2'])
+    assert api.option('ip_admin_eth0.netmask_admin_eth0', 0).value.get() is None
+    assert api.option('ip_admin_eth0.ip_admin_eth0').value.get() == ['192.168.1.2']
+    #
+    api.option('ip_admin_eth0.ip_admin_eth0').value.set(['192.168.1.2', '192.168.1.1'])
+    assert api.option('ip_admin_eth0.netmask_admin_eth0', 0).value.get() is None
+    raises(PropertiesOptionError, "api.option('ip_admin_eth0.netmask_admin_eth0', 1).value.get()")
+    #
+    api.option('ip_admin_eth0.ip_admin_eth0').value.set(['192.168.1.2', '192.168.1.2'])
+    assert api.option('ip_admin_eth0.netmask_admin_eth0', 0).value.get() is None
+    assert api.option('ip_admin_eth0.netmask_admin_eth0', 1).value.get() is None
+    api.option('ip_admin_eth0.netmask_admin_eth0', 1).value.set('255.255.255.255')
+    assert api.option('ip_admin_eth0.netmask_admin_eth0', 1).value.get() == '255.255.255.255'
+    assert api.value.dict() == {'ip_admin_eth0.ip_admin_eth0': ['192.168.1.2', '192.168.1.2'],
+                                'ip_admin_eth0.netmask_admin_eth0': [None, '255.255.255.255']}
+    #
+    api.option('ip_admin_eth0.ip_admin_eth0').value.set(['192.168.1.2', '192.168.1.1'])
+    assert api.option('ip_admin_eth0.netmask_admin_eth0', 0).value.get() is None
+    raises(PropertiesOptionError, "api.option('ip_admin_eth0.netmask_admin_eth0', 1).value.get()")
+    ret = api.value.dict()
+    assert set(ret.keys()) == set(['ip_admin_eth0.ip_admin_eth0', 'ip_admin_eth0.netmask_admin_eth0'])
+    assert ret['ip_admin_eth0.ip_admin_eth0'] == ['192.168.1.2', '192.168.1.1']
+    assert len(ret['ip_admin_eth0.netmask_admin_eth0']) == 2
+    assert ret['ip_admin_eth0.netmask_admin_eth0'][0] is None
+    assert isinstance(ret['ip_admin_eth0.netmask_admin_eth0'][1], PropertiesOptionError)
+    del ret['ip_admin_eth0.netmask_admin_eth0'][1]
+    del ret['ip_admin_eth0.netmask_admin_eth0'][0]
+    del ret['ip_admin_eth0.netmask_admin_eth0']
+    #
+    api.option('ip_admin_eth0.netmask_admin_eth0', 0).value.set('255.255.255.255')
+    ret = api.value.dict()
+    assert set(ret.keys()) == set(['ip_admin_eth0.ip_admin_eth0', 'ip_admin_eth0.netmask_admin_eth0'])
+    assert ret['ip_admin_eth0.ip_admin_eth0'] == ['192.168.1.2', '192.168.1.1']
+    assert len(ret['ip_admin_eth0.netmask_admin_eth0']) == 2
+    assert ret['ip_admin_eth0.netmask_admin_eth0'][0] == '255.255.255.255'
+    assert isinstance(ret['ip_admin_eth0.netmask_admin_eth0'][1], PropertiesOptionError)
+    del ret['ip_admin_eth0.netmask_admin_eth0'][1]
+    del ret['ip_admin_eth0.netmask_admin_eth0'][0]
+    del ret['ip_admin_eth0.netmask_admin_eth0']
+
+
 def test_leadership_requires_both():
     ip_admin = StrOption('ip_admin_eth0', "ip réseau autorisé")
     ip_admin_eth0 = StrOption('ip_admin_eth0', "ip réseau autorisé", multi=True,
@@ -1037,7 +1216,7 @@ def test_leadership_requires_properties():
     netmask_admin_eth0 = StrOption('netmask_admin_eth0', "masque du sous-réseau", multi=True,
                                    requires=[{'option': ip_admin_eth0, 'expected': '192.168.1.1', 'action': 'disabled'}])
     Leadership('ip_admin_eth0', '', [ip_admin_eth0, netmask_admin_eth0], properties=('hidden',),
-                 requires=[{'option': ip_admin, 'expected': '192.168.1.1', 'action': 'disabled'}])
+               requires=[{'option': ip_admin, 'expected': '192.168.1.1', 'action': 'disabled'}])
 
 
 def test_leadership_requires_leader():
@@ -1068,6 +1247,34 @@ def test_leadership_requires_leader():
     assert api.value.dict() == {'activate': False}
 
 
+def test_leadership_requires_leader_callback():
+    activate = BoolOption('activate', "Activer l'accès au réseau", True)
+    ip_admin_eth0 = StrOption('ip_admin_eth0', "ip réseau autorisé", multi=True,
+                              requires=[{'callback': calc_value, 'callback_params': Params(ParamOption(activate)), 'expected': False, 'action': 'disabled'}])
+    netmask_admin_eth0 = StrOption('netmask_admin_eth0', "masque du sous-réseau", multi=True)
+    interface1 = Leadership('ip_admin_eth0', '', [ip_admin_eth0, netmask_admin_eth0])
+    maconfig = OptionDescription('toto', '', [activate, interface1])
+    api = Config(maconfig)
+    api.property.read_write()
+    #
+    assert api.option('ip_admin_eth0.ip_admin_eth0').value.get() == []
+    api.option('ip_admin_eth0.ip_admin_eth0').value.set(['192.168.1.2'])
+    assert api.option('ip_admin_eth0.netmask_admin_eth0', 0).value.get() is None
+    assert api.option('ip_admin_eth0.ip_admin_eth0').value.get() == ['192.168.1.2']
+    #
+    api.option('activate').value.set(False)
+    raises(PropertiesOptionError, "api.option('ip_admin_eth0.ip_admin_eth0').value.get()")
+    raises(PropertiesOptionError, "api.option('ip_admin_eth0.netmask_admin_eth0', 0).value.get()")
+    #
+    api.option('activate').value.set(True)
+    assert api.option('ip_admin_eth0.netmask_admin_eth0', 0).value.get() is None
+    #
+    api.option('activate').value.set(False)
+    raises(PropertiesOptionError, "api.option('ip_admin_eth0.ip_admin_eth0').value.get()")
+    raises(PropertiesOptionError, "api.option('ip_admin_eth0.netmask_admin_eth0', 0).value.get()")
+    assert api.value.dict() == {'activate': False}
+
+
 def test_leadership_requires_leadership():
     activate = BoolOption('activate', "Activer l'accès au réseau", True)
     ip_admin_eth0 = StrOption('ip_admin_eth0', "ip réseau autorisé", multi=True)
@@ -1096,6 +1303,34 @@ def test_leadership_requires_leadership():
     assert api.value.dict() == {'activate': False}
 
 
+def test_leadership_requires_leadership_callback():
+    activate = BoolOption('activate', "Activer l'accès au réseau", True)
+    ip_admin_eth0 = StrOption('ip_admin_eth0', "ip réseau autorisé", multi=True)
+    netmask_admin_eth0 = StrOption('netmask_admin_eth0', "masque du sous-réseau", multi=True)
+    interface1 = Leadership('ip_admin_eth0', '', [ip_admin_eth0, netmask_admin_eth0],
+                            requires=[{'callback': calc_value, 'callback_params': Params(ParamOption(activate)), 'expected': False, 'action': 'disabled'}])
+    maconfig = OptionDescription('toto', '', [activate, interface1])
+    api = Config(maconfig)
+    api.property.read_write()
+    #
+    assert api.option('ip_admin_eth0.ip_admin_eth0').value.get() == []
+    api.option('ip_admin_eth0.ip_admin_eth0').value.set(['192.168.1.2'])
+    assert api.option('ip_admin_eth0.netmask_admin_eth0', 0).value.get() is None
+    assert api.option('ip_admin_eth0.ip_admin_eth0').value.get() == ['192.168.1.2']
+    #
+    api.option('activate').value.set(False)
+    raises(PropertiesOptionError, "api.option('ip_admin_eth0.ip_admin_eth0').value.get()")
+    raises(PropertiesOptionError, "api.option('ip_admin_eth0.netmask_admin_eth0', 0).value.get()")
+    #
+    api.option('activate').value.set(True)
+    assert api.option('ip_admin_eth0.netmask_admin_eth0', 0).value.get() is None
+    #
+    api.option('activate').value.set(False)
+    raises(PropertiesOptionError, "api.option('ip_admin_eth0.ip_admin_eth0').value.get()")
+    raises(PropertiesOptionError, "api.option('ip_admin_eth0.netmask_admin_eth0', 0).value.get()")
+    assert api.value.dict() == {'activate': False}
+
+
 def test_leadership_requires_no_leader():
     activate = BoolOption('activate', "Activer l'accès au réseau", True)
     ip_admin_eth0 = StrOption('ip_admin_eth0', "ip réseau autorisé", multi=True)
@@ -1125,6 +1360,40 @@ def test_leadership_requires_no_leader():
     assert api.value.dict() == {'ip_admin_eth0.ip_admin_eth0': ['192.168.1.2', '192.168.1.1'], 'activate': False}
 
 
+def test_leadership_requires_no_leader_callback():
+    activate = BoolOption('activate', "Activer l'accès au réseau", True)
+    ip_admin_eth0 = StrOption('ip_admin_eth0', "ip réseau autorisé", multi=True)
+    netmask_admin_eth0 = StrOption('netmask_admin_eth0', "masque du sous-réseau", multi=True,
+                                   requires=[{'callback': calc_value, 'callback_params': Params(ParamOption(activate)), 'expected': False, 'action': 'disabled'}])
+    interface1 = Leadership('ip_admin_eth0', '', [ip_admin_eth0, netmask_admin_eth0])
+    maconfig = OptionDescription('toto', '', [activate, interface1])
+    api = Config(maconfig)
+    api.property.read_write()
+    assert api.option('ip_admin_eth0.ip_admin_eth0').value.get() == []
+    api.option('ip_admin_eth0.ip_admin_eth0').value.set(['192.168.1.2'])
+    assert api.option('ip_admin_eth0.netmask_admin_eth0', 0).value.get() is None
+    assert api.option('ip_admin_eth0.ip_admin_eth0').value.get() == ['192.168.1.2']
+    api.option('activate').value.set(False)
+    api.option('ip_admin_eth0.ip_admin_eth0').value.set(['192.168.1.2', '192.168.1.1'])
+    assert api.option('ip_admin_eth0.ip_admin_eth0').value.get() == ['192.168.1.2', '192.168.1.1']
+    raises(PropertiesOptionError, "api.option('ip_admin_eth0.netmask_admin_eth0', 0).value.get()")
+    raises(PropertiesOptionError, "api.option('ip_admin_eth0.netmask_admin_eth0', 1).value.get()")
+    api.option('activate').value.set(True)
+    assert api.option('ip_admin_eth0.netmask_admin_eth0', 0).value.get() is None
+    assert api.option('ip_admin_eth0.netmask_admin_eth0', 1).value.get() is None
+    api.option('ip_admin_eth0.netmask_admin_eth0', 1).value.set('255.255.255.255')
+    assert api.option('ip_admin_eth0.netmask_admin_eth0', 1).value.get() == '255.255.255.255'
+    api.option('activate').value.set(False)
+    raises(PropertiesOptionError, "api.option('ip_admin_eth0.netmask_admin_eth0', 0).value.get()")
+    raises(PropertiesOptionError, "api.option('ip_admin_eth0.netmask_admin_eth0', 1).value.get()")
+    dico = api.value.dict()
+    assert set(dico.keys()) == {'activate', 'ip_admin_eth0.ip_admin_eth0', 'ip_admin_eth0.netmask_admin_eth0'}
+    dico['ip_admin_eth0.ip_admin_eth0'] == ['192.168.1.2', '192.168.1.1']
+    dico['activate'] == False
+    del dico['ip_admin_eth0.netmask_admin_eth0'][1]
+    del dico['ip_admin_eth0.netmask_admin_eth0'][0]
+
+
 def test_leadership_requires_complet():
     optiontoto = StrOption('unicodetoto', "Unicode leader")
     option = StrOption('unicode', "Unicode leader", multi=True)
@@ -1212,6 +1481,106 @@ def test_leadership_requires_complet():
     del dico['options.unicode.unicode7']
 
 
+def test_leadership_requires_complet_callback():
+    optiontoto = StrOption('unicodetoto', "Unicode leader")
+    option = StrOption('unicode', "Unicode leader", multi=True)
+    option1 = StrOption('unicode1', "Unicode follower 1", multi=True)
+    option2 = StrOption('unicode2', "Values 'test' must show 'Unicode follower 3'", multi=True)
+    option3 = StrOption('unicode3', "Unicode follower 3", requires=[{'callback': calc_value,
+                                                                     'callback_params': Params(ParamOption(option)),
+                                                                     'expected': u'test',
+                                                                     'action': 'hidden',
+                                                                     'inverse': True}],
+                        multi=True)
+    option4 = StrOption('unicode4', "Unicode follower 4", requires=[{'callback': calc_value,
+                                                                     'callback_params': Params(ParamOption(option2)),
+                                                                     'expected': u'test',
+                                                                     'action': 'hidden',
+                                                                     'inverse': True}],
+                        multi=True)
+    option5 = StrOption('unicode5', "Unicode follower 5", requires=[{'callback': calc_value,
+                                                                     'callback_params': Params(ParamOption(optiontoto)),
+                                                                     'expected': u'test',
+                                                                     'action': 'hidden',
+                                                                     'inverse': True}],
+                        multi=True)
+    option6 = StrOption('unicode6', "Unicode follower 6", requires=[{'callback': calc_value,
+                                                                     'callback_params': Params(ParamOption(optiontoto)),
+                                                                     'expected': u'test',
+                                                                     'action': 'hidden',
+                                                                     'inverse': True},
+                                                                    {'callback': calc_value,
+                                                                     'callback_params': Params(ParamOption(option2)),
+                                                                     'expected': u'test',
+                                                                     'action': 'hidden',
+                                                                     'inverse': True}],
+                        multi=True)
+    option7 = StrOption('unicode7', "Unicode follower 7", requires=[{'callback': calc_value,
+                                                                     'callback_params': Params(ParamOption(option2)),
+                                                                     'expected': u'test',
+                                                                     'action': 'hidden',
+                                                                     'inverse': True},
+                                                                    {'callback': calc_value,
+                                                                     'callback_params': Params(ParamOption(optiontoto)),
+                                                                     'expected': u'test',
+                                                                     'action': 'hidden',
+                                                                     'inverse': True}],
+                        multi=True)
+    descr1 = Leadership("unicode", "Common configuration 1",
+                        [option, option1, option2, option3, option4, option5, option6, option7])
+    descr = OptionDescription("options", "Common configuration 2", [descr1, optiontoto])
+    descr = OptionDescription("unicode1_leadership_requires", "Leader followers with Unicode follower 3 hidden when Unicode follower 2 is test", [descr])
+    config = Config(descr)
+    config.property.read_write()
+    config.option('options.unicode.unicode').value.set(['test', 'trah'])
+    config.option('options.unicode.unicode2', 0).value.set('test')
+    dico = config.value.dict()
+    assert dico.keys() == set(['options.unicode.unicode', 'options.unicode.unicode1', 'options.unicode.unicode2', 'options.unicode.unicode3', 'options.unicode.unicode4', 'options.unicode.unicode5', 'options.unicode.unicode6', 'options.unicode.unicode7', 'options.unicodetoto'])
+    assert dico['options.unicode.unicode'] == ['test', 'trah']
+    assert dico['options.unicode.unicode1'] == [None, None]
+    assert dico['options.unicode.unicode2'] == ['test', None]
+    assert dico['options.unicode.unicode3'][0] is None
+    assert isinstance(dico['options.unicode.unicode3'][1], PropertiesOptionError)
+    assert dico['options.unicode.unicode4'][0] is None
+    assert isinstance(dico['options.unicode.unicode4'][1], PropertiesOptionError)
+    assert dico['options.unicodetoto'] is None
+    del dico['options.unicode.unicode3'][1]
+    del dico['options.unicode.unicode3']
+    del dico['options.unicode.unicode4'][1]
+    del dico['options.unicode.unicode4']
+    del dico['options.unicode.unicode5'][0]
+    del dico['options.unicode.unicode5'][0]
+    del dico['options.unicode.unicode6'][0]
+    del dico['options.unicode.unicode6'][0]
+    del dico['options.unicode.unicode7'][0]
+    del dico['options.unicode.unicode7'][0]
+    #
+    config.option('options.unicodetoto').value.set('test')
+    dico = config.value.dict()
+    assert dico.keys() == set(['options.unicode.unicode', 'options.unicode.unicode1', 'options.unicode.unicode2', 'options.unicode.unicode3', 'options.unicode.unicode4', 'options.unicode.unicode5', 'options.unicode.unicode6', 'options.unicode.unicode7', 'options.unicodetoto'])
+    assert dico['options.unicode.unicode'] == ['test', 'trah']
+    assert dico['options.unicode.unicode1'] == [None, None]
+    assert dico['options.unicode.unicode2'] == ['test', None]
+    assert dico['options.unicode.unicode3'][0] is None
+    assert isinstance(dico['options.unicode.unicode3'][1], PropertiesOptionError)
+    assert dico['options.unicode.unicode4'][0] is None
+    assert isinstance(dico['options.unicode.unicode4'][1], PropertiesOptionError)
+    assert dico['options.unicode.unicode5'] == [None, None]
+    assert dico['options.unicode.unicode6'][0] is None
+    assert isinstance(dico['options.unicode.unicode6'][1], PropertiesOptionError)
+    assert dico['options.unicode.unicode7'][0] is None
+    assert isinstance(dico['options.unicode.unicode7'][1], PropertiesOptionError)
+    assert dico['options.unicodetoto'] == 'test'
+    del dico['options.unicode.unicode3'][1]
+    del dico['options.unicode.unicode3']
+    del dico['options.unicode.unicode4'][1]
+    del dico['options.unicode.unicode4']
+    del dico['options.unicode.unicode6'][1]
+    del dico['options.unicode.unicode6']
+    del dico['options.unicode.unicode7'][1]
+    del dico['options.unicode.unicode7']
+
+
 def test_leadership_requires_transitive():
     optiontoto = StrOption('unicodetoto', "Unicode leader")
     option = StrOption('unicode', "Unicode leader", multi=True)
@@ -1325,3 +1694,124 @@ def test_leadership_requires_transitive():
     del (dico['options.unicode.unicode4'][2])
     del (dico['options.unicode.unicode4'][1])
     del (dico['options.unicode.unicode4'][0])
+
+
+def test_leadership_requires_transitive_callback():
+    optiontoto = StrOption('unicodetoto', "Unicode leader")
+    option = StrOption('unicode', "Unicode leader", multi=True)
+    option1 = StrOption('unicode1', "Unicode follower 1", multi=True)
+    option2 = StrOption('unicode2', "Unicode follower 2", requires=[{'callback': calc_value,
+                                                                     'callback_params': Params(ParamOption(optiontoto)),
+                                                                     'expected': u'test',
+                                                                     'action': 'disabled',
+                                                                     'transitive': True,
+                                                                     'inverse': True}],
+                        multi=True)
+    option3 = StrOption('unicode3', "Unicode follower 3", requires=[{'callback': calc_value,
+                                                                     'callback_params': Params(ParamOption(option2)),
+                                                                     'expected': u'test',
+                                                                     'action': 'disabled',
+                                                                     'transitive': True,
+                                                                     'inverse': True}],
+                        multi=True)
+    option4 = StrOption('unicode4', "Unicode follower 4", requires=[{'callback': calc_value,
+                                                                     'callback_params': Params(ParamOption(option3)),
+                                                                     'expected': u'test',
+                                                                     'action': 'disabled',
+                                                                     'transitive': True,
+                                                                     'inverse': True}],
+                        multi=True)
+    descr1 = Leadership("unicode", "Common configuration 1",
+                        [option, option1, option2, option3, option4])
+    descr = OptionDescription("options", "Common configuration 2", [descr1, optiontoto])
+    descr = OptionDescription("unicode1", "", [descr])
+    config = Config(descr)
+    config.property.read_write()
+    assert config.value.dict() == {'options.unicode.unicode': [], 'options.unicode.unicode1': [], 'options.unicode.unicode2': [], 'options.unicode.unicode3': [], 'options.unicode.unicode4': [], 'options.unicodetoto': None}
+    #
+    config.option('options.unicodetoto').value.set('test')
+    assert config.value.dict() == {'options.unicode.unicode': [], 'options.unicode.unicode1': [], 'options.unicode.unicode2': [], 'options.unicode.unicode3': [], 'options.unicode.unicode4': [], 'options.unicodetoto': 'test'}
+    #
+    config.option('options.unicode.unicode').value.set(['a', 'b', 'c'])
+    dico = config.value.dict()
+    assert list(dico.keys()) == ['options.unicode.unicode', 'options.unicode.unicode1', 'options.unicode.unicode2', 'options.unicode.unicode3', 'options.unicode.unicode4', 'options.unicodetoto']
+    assert dico['options.unicodetoto'] == 'test'
+    assert dico['options.unicode.unicode'] == ['a', 'b', 'c']
+    assert dico['options.unicode.unicode1'] == [None, None, None]
+    assert dico['options.unicode.unicode2'] == [None, None, None]
+    assert isinstance(dico['options.unicode.unicode3'][0], PropertiesOptionError)
+    assert isinstance(dico['options.unicode.unicode3'][1], PropertiesOptionError)
+    assert isinstance(dico['options.unicode.unicode3'][2], PropertiesOptionError)
+    assert isinstance(dico['options.unicode.unicode4'][0], PropertiesOptionError)
+    assert isinstance(dico['options.unicode.unicode4'][1], PropertiesOptionError)
+    assert isinstance(dico['options.unicode.unicode4'][2], PropertiesOptionError)
+    del (dico['options.unicode.unicode3'][2])
+    del (dico['options.unicode.unicode3'][1])
+    del (dico['options.unicode.unicode3'][0])
+    del (dico['options.unicode.unicode4'][2])
+    del (dico['options.unicode.unicode4'][1])
+    del (dico['options.unicode.unicode4'][0])
+    #
+    config.option('options.unicode.unicode2', 1).value.set('test')
+    config.option('options.unicode.unicode3', 1).value.set('test')
+    dico = config.value.dict()
+    assert list(dico.keys()) == ['options.unicode.unicode', 'options.unicode.unicode1', 'options.unicode.unicode2', 'options.unicode.unicode3', 'options.unicode.unicode4', 'options.unicodetoto']
+    assert dico['options.unicodetoto'] == 'test'
+    assert dico['options.unicode.unicode'] == ['a', 'b', 'c']
+    assert dico['options.unicode.unicode1'] == [None, None, None]
+    assert dico['options.unicode.unicode2'] == [None, 'test', None]
+    assert isinstance(dico['options.unicode.unicode3'][0], PropertiesOptionError)
+    assert dico['options.unicode.unicode3'][1] == 'test'
+    assert isinstance(dico['options.unicode.unicode3'][2], PropertiesOptionError)
+    assert isinstance(dico['options.unicode.unicode4'][0], PropertiesOptionError)
+    assert dico['options.unicode.unicode4'][1] == None
+    assert isinstance(dico['options.unicode.unicode4'][2], PropertiesOptionError)
+    del (dico['options.unicode.unicode3'][2])
+    del (dico['options.unicode.unicode3'][1])
+    del (dico['options.unicode.unicode3'][0])
+    del (dico['options.unicode.unicode4'][2])
+    del (dico['options.unicode.unicode4'][1])
+    del (dico['options.unicode.unicode4'][0])
+    #
+    config.option('options.unicode.unicode2', 1).value.set('rah')
+    dico = config.value.dict()
+    assert list(dico.keys()) == ['options.unicode.unicode', 'options.unicode.unicode1', 'options.unicode.unicode2', 'options.unicode.unicode3', 'options.unicode.unicode4', 'options.unicodetoto']
+    assert dico['options.unicodetoto'] == 'test'
+    assert dico['options.unicode.unicode'] == ['a', 'b', 'c']
+    assert dico['options.unicode.unicode1'] == [None, None, None]
+    assert dico['options.unicode.unicode2'] == [None, 'rah', None]
+    assert isinstance(dico['options.unicode.unicode3'][0], PropertiesOptionError)
+    assert isinstance(dico['options.unicode.unicode3'][1], PropertiesOptionError)
+    assert isinstance(dico['options.unicode.unicode3'][2], PropertiesOptionError)
+    assert isinstance(dico['options.unicode.unicode4'][0], PropertiesOptionError)
+    assert isinstance(dico['options.unicode.unicode4'][1], PropertiesOptionError)
+    assert isinstance(dico['options.unicode.unicode4'][2], PropertiesOptionError)
+    del (dico['options.unicode.unicode3'][2])
+    del (dico['options.unicode.unicode3'][1])
+    del (dico['options.unicode.unicode3'][0])
+    del (dico['options.unicode.unicode4'][2])
+    del (dico['options.unicode.unicode4'][1])
+    del (dico['options.unicode.unicode4'][0])
+    #
+    config.option('options.unicode.unicode2', 1).value.set('test')
+    config.option('options.unicodetoto').value.set('rah')
+    dico = config.value.dict()
+    assert list(dico.keys()) == ['options.unicode.unicode', 'options.unicode.unicode1', 'options.unicode.unicode2', 'options.unicode.unicode3', 'options.unicode.unicode4', 'options.unicodetoto']
+    assert dico['options.unicodetoto'] == 'rah'
+    assert dico['options.unicode.unicode'] == ['a', 'b', 'c']
+    assert dico['options.unicode.unicode1'] == [None, None, None]
+    assert isinstance(dico['options.unicode.unicode3'][0], PropertiesOptionError)
+    assert isinstance(dico['options.unicode.unicode3'][1], PropertiesOptionError)
+    assert isinstance(dico['options.unicode.unicode3'][2], PropertiesOptionError)
+    assert isinstance(dico['options.unicode.unicode4'][0], PropertiesOptionError)
+    assert isinstance(dico['options.unicode.unicode4'][1], PropertiesOptionError)
+    assert isinstance(dico['options.unicode.unicode4'][2], PropertiesOptionError)
+    del (dico['options.unicode.unicode2'][2])
+    del (dico['options.unicode.unicode2'][1])
+    del (dico['options.unicode.unicode2'][0])
+    del (dico['options.unicode.unicode3'][2])
+    del (dico['options.unicode.unicode3'][1])
+    del (dico['options.unicode.unicode3'][0])
+    del (dico['options.unicode.unicode4'][2])
+    del (dico['options.unicode.unicode4'][1])
+    del (dico['options.unicode.unicode4'][0])
diff --git a/tiramisu/api.py b/tiramisu/api.py
index bc0e1ab..b91f39a 100644
--- a/tiramisu/api.py
+++ b/tiramisu/api.py
@@ -465,8 +465,9 @@ class _TiramisuOptionValueOption:
         if isinstance(value, list):
             while undefined in value:
                 idx = value.index(undefined)
-                value[idx] = values.getdefaultvalue(self._option_bag,
-                                                    force_index=idx)
+                soption_bag = self._option_bag.copy()
+                soption_bag.index = idx
+                value[idx] = values.getdefaultvalue(soption_bag)
         elif value == undefined:
             value = values.getdefaultvalue(self._option_bag)
         self._subconfig.setattr(value,
diff --git a/tiramisu/autolib.py b/tiramisu/autolib.py
index dc2af0c..ffdf87d 100644
--- a/tiramisu/autolib.py
+++ b/tiramisu/autolib.py
@@ -90,11 +90,11 @@ def manager_callback(callbk: Union[ParamOption, ParamValue],
             return value[index]
         return value
     except PropertiesOptionError as err:
-        # raise because must not add value None in carry_out_calculation
+        # raise PropertiesOptionError (which is catched) because must not add value None in carry_out_calculation
         if callbk.notraisepropertyerror:
             raise err
         raise ConfigError(_('unable to carry out a calculation for "{}"'
-                            ', {}').format(option.impl_get_display_name(), err))
+                            ', {}').format(option.impl_get_display_name(), err), err)
 
 
 def carry_out_calculation(option,
diff --git a/tiramisu/error.py b/tiramisu/error.py
index 940eee2..1e27319 100644
--- a/tiramisu/error.py
+++ b/tiramisu/error.py
@@ -116,7 +116,7 @@ class PropertiesOptionError(AttributeError):
                                         self._name,
                                         prop_msg,
                                         msg))
-        del self._requires, self._opt_type, self._name, self._option_bag
+        del self._requires, self._opt_type, self._name
         del self._settings, self._orig_opt
         return self.msg
 
@@ -127,7 +127,11 @@ class ConfigError(Exception):
     """attempt to change an option's owner without a value
     or in case of `_cfgimpl_descr` is None
     or if a calculation cannot be carried out"""
-    pass
+    def __init__(self,
+                 exp,
+                 ori_err=None):
+        super().__init__(exp)
+        self.ori_err = ori_err
 
 
 class ConflictError(Exception):
diff --git a/tiramisu/function.py b/tiramisu/function.py
index 94837a1..1be9e6e 100644
--- a/tiramisu/function.py
+++ b/tiramisu/function.py
@@ -49,9 +49,12 @@ class Param:
 
 
 class ParamOption(Param):
-    __slots__ = ('option', 'notraisepropertyerror')
-    def __init__(self, option, notraisepropertyerror=False):
-        if not hasattr(option, 'impl_is_symlinkoption'):
+    __slots__ = ('option',
+                 'notraisepropertyerror')
+    def __init__(self,
+                 option: 'Option',
+                 notraisepropertyerror: bool=False) -> None:
+        if __debug__ and not hasattr(option, 'impl_is_symlinkoption'):
             raise ValueError(_('paramoption needs an option not {}').format(type(option)))
         if option.impl_is_symlinkoption():
             cur_opt = option.impl_getopt()
@@ -95,6 +98,7 @@ def calc_value(*args: List[Any],
                join: Optional[str]=None,
                min_args_len: Optional[int]=None,
                operator: Optional[str]=None,
+               index: Optional[int]=None,
                **kwargs) -> Any:
     """calculate value
     :param multi: value returns must be a list of value
@@ -181,7 +185,6 @@ def calc_value(*args: List[Any],
     >>> cfg.value.dict()
     {'val1': 'val1', 'val2': 'val1', 'val3': ['val1']}
 
-
     * you want to join two values with '.'
     >>> from tiramisu import calc_value, StrOption, OptionDescription, Config, Params, ParamOption, ParamValue
     >>> val1 = StrOption('val1', "", 'val1')
@@ -305,6 +308,11 @@ def calc_value(*args: List[Any],
             value = None
         else:
             value = value[0]
+            if isinstance(value, list) and index is not None:
+                if len(value) > index:
+                    value = value[index]
+                else:
+                    value = None
     elif None in value and not allow_none:
         value = []
     elif remove_duplicate_value:
diff --git a/tiramisu/option/baseoption.py b/tiramisu/option/baseoption.py
index bbcef07..e44a7f4 100644
--- a/tiramisu/option/baseoption.py
+++ b/tiramisu/option/baseoption.py
@@ -170,7 +170,7 @@ class Base:
                     param.option._add_dependency(self)
                     if type_ == 'validator':
                         self._has_dependency = True
-        is_multi = self.impl_is_dynoptiondescription() or self.impl_is_multi()
+        is_multi = self.impl_is_optiondescription() or self.impl_is_multi()
         func_args, func_kwargs, func_positional, func_keyword = self._get_function_args(calculator)
         calculator_args, calculator_kwargs = self._get_parameters_args(calculator_params, add_value)
         # remove knowned kwargs
@@ -253,13 +253,14 @@ class Base:
     def _impl_set_callback(self,
                            callback: Callable,
                            callback_params: Optional[Params]=None) -> None:
-        if callback is None and callback_params is not None:
-            raise ValueError(_("params defined for a callback function but "
-                               "no callback defined"
-                               ' yet for option "{0}"').format(
-                                   self.impl_getname()))
-        self._validate_calculator(callback,
-                                  callback_params)
+        if __debug__:
+            if callback is None and callback_params is not None:
+                raise ValueError(_("params defined for a callback function but "
+                                   "no callback defined"
+                                   ' yet for option "{0}"').format(
+                                       self.impl_getname()))
+            self._validate_calculator(callback,
+                                      callback_params)
         if callback is not None:
             callback_params = self._build_calculator_params(callback,
                                                             callback_params,
@@ -443,17 +444,25 @@ def validate_requires_arg(new_option: BaseOption,
                      the description of the requires dictionary
     """
     def get_option(require):
-        option = require['option']
-        if option == 'self':
-            option = new_option
-        if not isinstance(option, BaseOption):
-            raise ValueError(_('malformed requirements '
-                               'must be an option in option {0}').format(name))
-        if not multi and option.impl_is_multi():
-            raise ValueError(_('malformed requirements '
-                               'multi option must not set '
-                               'as requires of non multi option {0}').format(name))
-        option._add_dependency(new_option)
+        if 'option' in require:
+            option = require['option']
+            if option == 'self':
+                option = new_option
+            if __debug__:
+                if not isinstance(option, BaseOption):
+                    raise ValueError(_('malformed requirements '
+                                       'must be an option in option {0}').format(name))
+                if not multi and option.impl_is_multi():
+                    raise ValueError(_('malformed requirements '
+                                       'multi option must not set '
+                                       'as requires of non multi option {0}').format(name))
+            option._add_dependency(new_option)
+        else:
+            callback = require['callback']
+            callback_params = new_option._build_calculator_params(callback,
+                                                                  require.get('callback_params'),
+                                                                  'callback')
+            option = (callback, callback_params)
         return option
 
     def _set_expected(action,
@@ -482,11 +491,11 @@ def validate_requires_arg(new_option: BaseOption,
         operator = get_operator(require)
         if isinstance(expected, list):
             for exp in expected:
-                if set(exp.keys()) != {'option', 'value'}:
+                if __debug__ and set(exp.keys()) != {'option', 'value'}:
                     raise ValueError(_('malformed requirements expected must have '
                                        'option and value for option {0}').format(name))
                 option = get_option(exp)
-                if option is not None:
+                if __debug__:
                     try:
                         option._validate(exp['value'], undefined)
                     except ValueError as err:
@@ -502,7 +511,7 @@ def validate_requires_arg(new_option: BaseOption,
                               operator)
         else:
             option = get_option(require)
-            if expected is not None:
+            if __debug__ and not isinstance(option, tuple) and expected is not None:
                 try:
                     option._validate(expected, undefined)
                 except ValueError as err:
@@ -560,25 +569,29 @@ def validate_requires_arg(new_option: BaseOption,
     # start parsing all requires given by user (has dict)
     # transforme it to a tuple
     for require in requires:
-        if not isinstance(require, dict):
-            raise ValueError(_("malformed requirements type for option:"
-                               " {0}, must be a dict").format(name))
-        valid_keys = ('option', 'expected', 'action', 'inverse', 'transitive',
-                      'same_action', 'operator')
-        unknown_keys = frozenset(require.keys()) - frozenset(valid_keys)
-        if unknown_keys != frozenset():
-            raise ValueError(_('malformed requirements for option: {0}'
-                             ' unknown keys {1}, must only '
-                             '{2}').format(name,
-                                           unknown_keys,
-                                           valid_keys))
-        # prepare all attributes
-        if not ('expected' in require and isinstance(require['expected'], list)) and \
-                not ('option' in require and 'expected' in require) or \
-                'action' not in require:
-            raise ValueError(_("malformed requirements for option: {0}"
-                               " require must have option, expected and"
-                               " action keys").format(name))
+        if __debug__:
+            if not isinstance(require, dict):
+                raise ValueError(_("malformed requirements type for option:"
+                                   " {0}, must be a dict").format(name))
+            valid_keys = ('option', 'expected', 'action', 'inverse', 'transitive',
+                          'same_action', 'operator', 'callback', 'callback_params')
+            unknown_keys = frozenset(require.keys()) - frozenset(valid_keys)
+            if unknown_keys != frozenset():
+                raise ValueError(_('malformed requirements for option: {0}'
+                                 ' unknown keys {1}, must only '
+                                 '{2}').format(name,
+                                               unknown_keys,
+                                               valid_keys))
+            # {'expected': ..., 'option': ..., 'action': ...}
+            # {'expected': [{'option': ..., 'value': ...}, ...}], 'action': ...}
+            # {'expected': ..., 'callback': ..., 'action': ...}
+            if not 'expected' in require or not 'action' in require or \
+                    not (isinstance(require['expected'], list) or \
+                        'option' in require or \
+                        'callback' in require):
+                raise ValueError(_("malformed requirements for option: {0}"
+                                   " require must have option, expected and"
+                                   " action keys").format(name))
         action = get_action(require)
         config_action.add(action)
         if action not in ret_requires:
diff --git a/tiramisu/option/leadership.py b/tiramisu/option/leadership.py
index d7c0a3a..86e0efb 100644
--- a/tiramisu/option/leadership.py
+++ b/tiramisu/option/leadership.py
@@ -109,7 +109,7 @@ class Leadership(OptionDescription):
             for requires_ in getattr(self, '_requires', ()):
                 for require in requires_:
                     for require_opt, values in require[0]:
-                        if require_opt.impl_is_multi() and require_opt.impl_get_leadership():
+                        if not isinstance(require_opt, tuple) and require_opt.impl_is_multi() and require_opt.impl_get_leadership():
                             raise ValueError(_('malformed requirements option "{0}" '
                                                'must not be in follower for "{1}"').format(
                                                    require_opt.impl_getname(),
diff --git a/tiramisu/option/optiondescription.py b/tiramisu/option/optiondescription.py
index b858fb3..e51d9d0 100644
--- a/tiramisu/option/optiondescription.py
+++ b/tiramisu/option/optiondescription.py
@@ -139,7 +139,7 @@ class CacheOptionDescription(BaseOption):
                                 # * current option must be a follower (and only a follower)
                                 # * option in require and current option must be in same leadership
                                 for require_opt, values in require[0]:
-                                    if require_opt.impl_is_multi():
+                                    if not isinstance(require_opt, tuple) and require_opt.impl_is_multi():
                                         if is_follower is None:
                                             is_follower = option.impl_is_follower()
                                             if is_follower:
diff --git a/tiramisu/setting.py b/tiramisu/setting.py
index 8ce365d..6e674ea 100644
--- a/tiramisu/setting.py
+++ b/tiramisu/setting.py
@@ -509,43 +509,59 @@ class Settings(object):
                 exps, action, inverse, transitive, same_action, operator = require
                 breaked = False
                 for option, expected in exps:
-                    if option.issubdyn():
-                        option = option.to_dynoption(option_bag.option.rootpath,
-                                                     option_bag.option.impl_getsuffix())
-                    reqpath = option.impl_getpath()
-                    #FIXME too later!
-                    if reqpath.startswith(option_bag.path + '.'):
-                        raise RequirementError(_("malformed requirements "
-                                                 "imbrication detected for option:"
-                                                 " '{0}' with requirement on: "
-                                                 "'{1}'").format(option_bag.path, reqpath))
-                    idx = None
-                    is_indexed = False
-                    if option.impl_is_follower():
-                        idx = option_bag.index
-                        if idx is None:
+                    if not isinstance(option, tuple):
+                        if option.issubdyn():
+                            option = option.to_dynoption(option_bag.option.rootpath,
+                                                         option_bag.option.impl_getsuffix())
+                        reqpath = option.impl_getpath()
+                        if __debug__ and reqpath.startswith(option_bag.path + '.'):
+                            # FIXME too later!
+                            raise RequirementError(_("malformed requirements "
+                                                     "imbrication detected for option:"
+                                                     " '{0}' with requirement on: "
+                                                     "'{1}'").format(option_bag.path, reqpath))
+                        idx = None
+                        is_indexed = False
+                        if option.impl_is_follower():
+                            idx = option_bag.index
+                            if idx is None:
+                                continue
+                        elif option.impl_is_leader() and option_bag.index is None:
                             continue
-                    elif option.impl_is_leader() and option_bag.index is None:
-                        continue
-                    elif option.impl_is_multi() and option_bag.index is not None:
-                        is_indexed = True
-                    config_bag = option_bag.config_bag.copy()
-                    soption_bag = OptionBag()
-                    soption_bag.set_option(option,
-                                           reqpath,
-                                           idx,
-                                           config_bag)
-                    if option_bag.option == option:
-                        soption_bag.config_bag.unrestraint()
-                        soption_bag.config_bag.remove_validation()
-                        soption_bag.apply_requires = False
+                        elif option.impl_is_multi() and option_bag.index is not None:
+                            is_indexed = True
+                        config_bag = option_bag.config_bag.copy()
+                        soption_bag = OptionBag()
+                        soption_bag.set_option(option,
+                                               reqpath,
+                                               idx,
+                                               config_bag)
+                        if option_bag.option == option:
+                            soption_bag.config_bag.unrestraint()
+                            soption_bag.config_bag.remove_validation()
+                            soption_bag.apply_requires = False
+                        else:
+                            soption_bag.config_bag.properties = soption_bag.config_bag.true_properties
+                            soption_bag.config_bag.set_permissive()
                     else:
-                        soption_bag.config_bag.properties = soption_bag.config_bag.true_properties
-                        soption_bag.config_bag.set_permissive()
+                        if not option_bag.option.impl_is_optiondescription() and option_bag.option.impl_is_follower():
+                            idx = option_bag.index
+                            if idx is None:
+                                continue
+                        is_indexed = False
                     try:
-                        value = context.getattr(reqpath,
-                                                soption_bag)
-                    except PropertiesOptionError as err:
+                        if not isinstance(option, tuple):
+                            value = context.getattr(reqpath,
+                                                    soption_bag)
+                        else:
+                            value = context.cfgimpl_get_values().carry_out_calculation(option_bag,
+                                                                                       option[0],
+                                                                                       option[1])
+                    except (PropertiesOptionError, ConfigError) as err:
+                        if isinstance(err, ConfigError):
+                            if not isinstance(err.ori_err, PropertiesOptionError):
+                                raise err
+                            err = err.ori_err
                         properties = err.proptype
                         # if not transitive, properties must be verify in current requires
                         # otherwise if same_action, property must be in properties
@@ -586,13 +602,19 @@ class Settings(object):
                                 inverse and value not in expected):
                             if operator != 'and':
                                 if readable:
-                                    if not inverse:
-                                        msg = _('the value of "{0}" is {1}')
+                                    display_value = display_list(expected, 'or', add_quote=True)
+                                    if isinstance(option, tuple):
+                                        if not inverse:
+                                            msg = _('the calculated value is {0}').format(display_value)
+                                        else:
+                                            msg = _('the calculated value is not {0}').format(display_value)
                                     else:
-                                        msg = _('the value of "{0}" is not {1}')
-                                    calc_properties.setdefault(action, []).append(
-                                        msg.format(option.impl_get_display_name(),
-                                                   display_list(expected, 'or', add_quote=True)))
+                                        name = option.impl_get_display_name()
+                                        if not inverse:
+                                            msg = _('the value of "{0}" is {1}').format(name, display_value)
+                                        else:
+                                            msg = _('the value of "{0}" is not {1}').format(name, display_value)
+                                    calc_properties.setdefault(action, []).append(msg)
                                 else:
                                     calc_properties.add(action)
                                     breaked = True
diff --git a/tiramisu/value.py b/tiramisu/value.py
index 6b07455..08f974d 100644
--- a/tiramisu/value.py
+++ b/tiramisu/value.py
@@ -16,10 +16,11 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 # ____________________________________________________________
 import weakref
-from typing import Optional
+from typing import Optional, Any, Callable
 from .error import ConfigError, PropertiesOptionError
 from .setting import owners, undefined, forbidden_owners, OptionBag, ConfigBag
 from .autolib import carry_out_calculation
+from .function import Params
 from .i18n import _
 
 
@@ -135,26 +136,48 @@ class Values(object):
         return self.getdefaultvalue(option_bag)
 
     def getdefaultvalue(self,
-                        option_bag,
-                        force_index: Optional[int]=None):
+                        option_bag):
         """get default value:
         - get meta config value or
         - get calculated value or
         - get default value
-        :param opt: the `option.Option()` object
-        :param path: path for `option.Option()` object
-        :type path: str
-        :param index: index of a multi/submulti
-        :type index: int
-        :returns: default value
         """
+        moption_bag = self._get_meta(option_bag)
+        if moption_bag:
+            # retrieved value from meta config
+            return moption_bag.config_bag.context.cfgimpl_get_values().get_cached_value(moption_bag)
+
+        if option_bag.option.impl_has_callback():
+            # default value is a calculated value
+            value = self.calculate_value(option_bag)
+            if value is not undefined:
+                return value
+
+        # now try to get default value:
+        value = option_bag.option.impl_getdefault()
+
+        # - if option is a submulti, return a list a list
+        # - if option is a multi, return a list
+        # - default value
+        if option_bag.option.impl_is_multi() and option_bag.index is not None:
+            # if index, must return good value for this index
+            if len(value) > option_bag.index:
+                value = value[option_bag.index]
+            else:
+                # no value for this index, retrieve default multi value
+                # default_multi is already a list for submulti
+                value = option_bag.option.impl_getdefault_multi()
+        return value
+
+    def calculate_value(self,
+                        option_bag: OptionBag) -> Any:
         def _reset_cache(_value):
             if not 'expire' in option_bag.properties:
                 return
             is_cache, cache_value = self._p_.getcache(option_bag.path,
                                                       None,
-                                                      index,
-                                                      config_bag.properties,
+                                                      option_bag.index,
+                                                      option_bag.config_bag.properties,
                                                       option_bag.properties,
                                                       'value')
             if not is_cache or cache_value == _value:
@@ -162,75 +185,55 @@ class Values(object):
                 # so do not invalidate cache
                 return
             # calculated value is a new value, so reset cache
-            config_bag.context.cfgimpl_reset_cache(option_bag)
+            option_bag.config_bag.context.cfgimpl_reset_cache(option_bag)
 
-        config_bag = option_bag.config_bag
-        opt = option_bag.option
-        if force_index is not None:
-            index = force_index
-        else:
-            index = option_bag.index
-        moption_bag = self._get_meta(option_bag)
-        if moption_bag:
-            # retrieved value from meta config
-            return moption_bag.config_bag.context.cfgimpl_get_values().get_cached_value(moption_bag)
-
-        if opt.impl_has_callback():
-            # if value has callback, calculate value
-            callback, callback_params = opt.impl_get_callback()
-            value = carry_out_calculation(opt,
-                                          callback=callback,
-                                          callback_params=callback_params,
-                                          index=index,
-                                          config_bag=config_bag,
-                                          fromconsistency=option_bag.fromconsistency)
-            if isinstance(value, list) and index is not None:
-                # if value is a list and index is set
-                if opt.impl_is_submulti() and (value == [] or not isinstance(value[0], list)):
-                    # return value only if it's a submulti and not a list of list
-                    _reset_cache(value)
-                    return value
-
-                if len(value) > index:
-                    # return the value for specified index if found
-                    _reset_cache(value[index])
-                    return value[index]
-                # there is no calculate value for this index,
-                # so return an other default value
-            else:
-                if opt.impl_is_submulti():
-                    if isinstance(value, list):
-                        # value is a list, but no index specified
-                        if (value != [] and not isinstance(value[0], list)):
-                            # if submulti, return a list of value
-                            value = [value]
-                    elif index is not None:
-                        # if submulti, return a list of value
-                        value = [value]
-                    else:
-                        # return a list of list for a submulti
-                        value = [[value]]
-                elif opt.impl_is_multi() and not isinstance(value, list) and index is None:
-                    # return a list for a multi
-                    value = [value]
+        # if value has callback, calculate value
+        callback, callback_params = option_bag.option.impl_get_callback()
+        value = self.carry_out_calculation(option_bag,
+                                           callback,
+                                           callback_params)
+        if isinstance(value, list) and option_bag.index is not None:
+            # if value is a list and index is set
+            if option_bag.option.impl_is_submulti() and (value == [] or not isinstance(value[0], list)):
+                # return value only if it's a submulti and not a list of list
                 _reset_cache(value)
                 return value
+            if len(value) > option_bag.index:
+                # return the value for specified index if found
+                _reset_cache(value[option_bag.index])
+                return value[option_bag.index]
+            # there is no calculate value for this index,
+            # so return an other default value
+        else:
+            if option_bag.option.impl_is_submulti():
+                if isinstance(value, list):
+                    # value is a list, but no index specified
+                    if (value != [] and not isinstance(value[0], list)):
+                        # if submulti, return a list of value
+                        value = [value]
+                elif option_bag.index is not None:
+                    # if submulti, return a list of value
+                    value = [value]
+                else:
+                    # return a list of list for a submulti
+                    value = [[value]]
+            elif option_bag.option.impl_is_multi() and not isinstance(value, list) and option_bag.index is None:
+                # return a list for a multi
+                value = [value]
+            _reset_cache(value)
+            return value
+        return undefined
 
-        # now try to get default value:
-        # - if opt is a submulti, return a list a list
-        # - if opt is a multi, return a list
-        # - default value
-        value = opt.impl_getdefault()
-        if opt.impl_is_multi() and index is not None:
-            # if index, must return good value for this index
-            if len(value) > index:
-                value = value[index]
-            else:
-                # no value for this index, retrieve default multi value
-                # default_multi is already a list for submulti
-                value = opt.impl_getdefault_multi()
-        return value
-
+    def carry_out_calculation(self,
+                              option_bag: OptionBag,
+                              callback: Callable,
+                              callback_params: Optional[Params]) -> Any:
+        return carry_out_calculation(option_bag.option,
+                                     callback=callback,
+                                     callback_params=callback_params,
+                                     index=option_bag.index,
+                                     config_bag=option_bag.config_bag,
+                                     fromconsistency=option_bag.fromconsistency)
     def isempty(self,
                 opt,
                 value,