diff --git a/src/Model/InitialConditions/InitialConditions.py b/src/Model/InitialConditions/InitialConditions.py
index 9c62b69ab67f3758a3ba158c3ed631ca0bba7688..f54c287fdf9d96aca74f8a82d8ba9fa1f9508902 100644
--- a/src/Model/InitialConditions/InitialConditions.py
+++ b/src/Model/InitialConditions/InitialConditions.py
@@ -95,7 +95,7 @@ class InitialConditions(object):
     def delete(self, data):
         self._data = list(
             filter(
-                lambda x: x in data,
+                lambda x: x not in data,
                 self._data
             )
         )
diff --git a/src/View/InitialConditions/UndoCommand.py b/src/View/InitialConditions/UndoCommand.py
index 8482bd9a245374bef56268e2f069e3862466d20d..480b3d43d30715242e2045748d3a750bff240076 100644
--- a/src/View/InitialConditions/UndoCommand.py
+++ b/src/View/InitialConditions/UndoCommand.py
@@ -44,7 +44,7 @@ class AddCommand(QUndoCommand):
             self._ics.insert(self._index, self._new)
 
 class DelCommand(QUndoCommand):
-    def __init__(self, ics, tab, rows):
+    def __init__(self, ics, rows):
         QUndoCommand.__init__(self)
 
         self._ics = ics
@@ -63,7 +63,7 @@ class DelCommand(QUndoCommand):
         self._ics.delete_i(self._rows)
 
 class SortCommand(QUndoCommand):
-    def __init__(self, ics, tab, _reverse):
+    def __init__(self, ics, _reverse):
         QUndoCommand.__init__(self)
 
         self._ics = ics
@@ -94,7 +94,7 @@ class SortCommand(QUndoCommand):
 
 
 class MoveCommand(QUndoCommand):
-    def __init__(self, ics, tab, up, i):
+    def __init__(self, ics, up, i):
         QUndoCommand.__init__(self)
 
         self._ics = ics
@@ -115,7 +115,7 @@ class MoveCommand(QUndoCommand):
 
 
 class PasteCommand(QUndoCommand):
-    def __init__(self, ics, tab, row, ic):
+    def __init__(self, ics, row, ic):
         QUndoCommand.__init__(self)
 
         self._ics = ics
@@ -132,7 +132,7 @@ class PasteCommand(QUndoCommand):
 
 
 class DuplicateCommand(QUndoCommand):
-    def __init__(self, ics, tab, rows, ic):
+    def __init__(self, ics, rows, ic):
         QUndoCommand.__init__(self)
 
         self._ics = ics