Merge branch 'master' of 192.168.15.97:codeq-problems

1 files changed, 10 insertions, 2 deletions

diff --git a/prolog/problems/family_relations/sister_2/common.py b/prolog/problems/family_relations/sister_2/common.py
index 627648c..c112a9c 100644
--- a/prolog/problems/family_relations/sister_2/common.py
+++ b/prolog/problems/family_relations/sister_2/common.py
@@ -23,8 +23,9 @@ sister(X, Y) :-
 hint_type = {
     'x_must_be_female': Hint('x_must_be_female'),
     'common_parent_needed': Hint('common_parent_needed'),
-    'y_can_be_of_any_gender': Hint('Y_can_be_of_any_gender'),
+    'y_can_be_of_any_gender': Hint('y_can_be_of_any_gender'),
     'x_y_must_be_different': Hint('x_y_must_be_different'),
+    'neq_used_too_early': Hint('neq_used_too_early'),
 }
 
 test_cases = [
@@ -121,10 +122,17 @@ def hint(program, solved_problems):
 
         # X and Y must be different
         # this is the last code-specific hint (when everything else doesn't trigger anymore)
-        if prolog.engine.ask_truth(engine_id,
+        if prolog.util.Token('NEQ', '\==') not in tokens and prolog.engine.ask_truth(engine_id,
             'setof(X, (member(X, [sally, nevia, vanessa]), sister(X, X)), L), length(L, 3)'):
             return [{'id': 'x_y_must_be_different'}]
 
+        # X and Y must be different, but the user used '\=='
+        # most likely this means that \== was used before X and Y are known
+        # this is the last code-specific hint (when everything else doesn't trigger anymore)
+        if prolog.util.Token('NEQ', '\==') in tokens and prolog.engine.ask_truth(engine_id,
+            'setof(X/Y, sister(X, Y), L), member(nevia/nevia, L), member(sally/sally, L), member(vanessa/vanessa, L)'):
+            return [{'id': 'neq_used_too_early'}]
+
         # last hints are connected with programming style
         # here, this means detecting such code:
         # parent(P1, X), parent(P2, Y), P1 == P2 (or P1 = P2)