Fix a bug with witness display

models.pl

@@ -1349,8 +1349,7 @@ test_wellformed([Molecule|Tail], Expression for Reaction) :-
 test_wf_reactant(Molecule, Expression) :-
   formal_derivation:derivate(Expression, Molecule, Derivative),
   (
-    \+(arithmetic_rules:always_negative(Derivative)),
-    !
+    \+(arithmetic_rules:always_negative(Derivative))
   ;
     format("Fail for wellformedness of ~w with ~w as reactant.~n", [Expression, Molecule]),
     fail
@@ -1363,8 +1362,7 @@ test_wf_reactant(Molecule, Expression) :-
 test_wf_inhibitor(Molecule, Expression) :-
   formal_derivation:derivate(Expression, Molecule, Derivative),
   (
-    \+(arithmetic_rules:always_positive(Derivative)),
-    !
+    \+(arithmetic_rules:always_positive(Derivative))
   ;
     format("Fail for wellformedness of ~w with ~w as inhibitor.~n", [Expression, Molecule]),
     fail
@@ -1375,8 +1373,7 @@ test_wf_inhibitor(Molecule, Expression) :-
 test_wf_other(Molecule, Expression) :-
   formal_derivation:derivate(Expression, Molecule, Derivative),
   (
-    is_null(Derivative),
-    !
+    is_null(Derivative)
   ;
     format("Fail for wellformedness of ~w with ~w as not present.~n", [Expression, Molecule]),
     fail