Figures and hints updated for mother/2 problem.

1 files changed, 6 insertions, 0 deletions

diff --git a/prolog/problems/family_relations/mother_2/common.py b/prolog/problems/family_relations/mother_2/common.py
index d819ef5..d943b9c 100644
--- a/prolog/problems/family_relations/mother_2/common.py
+++ b/prolog/problems/family_relations/mother_2/common.py
@@ -91,6 +91,12 @@ def hint(program, solved_problems):
             'findall(_, mother(X, Y), L), length(L, 50)'):
             return [{'id': 'or_instead_of_and'}]
 
+        # OR instead of AND written with two rules, namely:
+        #    (r1) mother(X, Y):- female(X).  (r2) mother(X, Y):- parent(X, Y).
+        if prolog.engine.ask_truth(engine_id,
+            'findall(_, mother(X, Y), L), length(L, 50)'):
+            return [{'id': 'or_instead_of_and_two_rules'}]
+
         # X must be female
         if prolog.engine.ask_truth(engine_id, 'male(X), mother(X, _)'):
             return [{'id': 'x_must_be_female'}]