Check_model detect nullify kinetics

models.pl

@@ -1347,6 +1347,12 @@ test_wellformed(_Molecules, 'MA'(_R) for _Reaction).
 
 test_wellformed([Molecule|Tail], Expression for Reaction) :-
   (
+    % detect null kinetics as a warning
+    is_null(Expression)
+  ->
+    format("WARNING: Some kinetics are detected as null: ~w~n", [Expression]),
+    fail
+  ;
     is_reactant(Molecule, Expression for Reaction)
   ->
     test_wf_reactant(Molecule, Expression)