4 files changed, 122 insertions, 6 deletions
diff --git a/prolog/problems/lists_advanced/len_2/common.py b/prolog/problems/lists_advanced/len_2/common.py
index 501a4f8..6caea98 100644
--- a/prolog/problems/lists_advanced/len_2/common.py
+++ b/prolog/problems/lists_advanced/len_2/common.py
@@ -24,6 +24,12 @@ hint_type = {
     'base_case': Hint('base_case'),
     'recursive_case': Hint('recursive_case'),
     'timeout': Hint('timeout'),
+    'arbitrary_base_case': Hint('arbitrary_base_case'),
+    'args_not_instantiated': Hint('arbitrary_base_case'),
+    '=_instead_of_is': Hint('=_instead_of_is'),
+    '+H_instead_of_+1': Hint('+H_instead_of_+1'),
+    'forcing_result_onto_recursion': Hint('forcing_result_onto_recursion'),
+    'same_var_on_both_sides_of_is': Hint('same_var_on_both_sides_of_is'),
 }
 
 test_cases = [
@@ -68,13 +74,41 @@ def hint(code, aux_code):
             return [{'id': 'eq_instead_of_equ_markup', 'start': m[0], 'end': m[1]} for m in marks] + \
                    [{'id': 'eq_instead_of_equ'}]
 
+        # target predicate seems to always be false
+        if not prolog.engine.ask_truthTO(engine_id, 'len(_, _)'):
+            return [{'id': 'predicate_always_false'}]
+
+        # arbitrary base case: len([], _)
+        if prolog.engine.ask_truthTO(engine_id, 'len([], q), len([], child(Q, q))'):
+            return [{'id': 'arbitrary_base_case'}]
+
         # missing/failed base case
         if not prolog.engine.ask_truthTO(engine_id, 'len([], 0)'):
             return [{'id': 'base_case'}]
 
-        # target predicate seems to always be false
-        if not prolog.engine.ask_truthTO(engine_id, 'len(_, _)'):
-            return [{'id': 'predicate_always_false'}]
+        # arguments not instantiated
+        reply, output = prolog.engine.ask(engine_id, 'len([a, b, c], Len)', timeout=1)
+        if reply.get('code') == 'instantiation_error':
+            return [{'id': 'args_not_instantiated'}]
+
+        # = instead of is
+        if prolog.engine.ask_truthTO(engine_id, 'len([qa, qb, qc, qd], _+_)'):
+            return [{'id': '=_instead_of_is'}]
+
+        # +H instead of +1
+        if prolog.engine.ask_truthTO(engine_id, 'len([1, 3, 9, 27, 81], 121)'):
+            return [{'id': '+H_instead_of_+1'}]
+
+        # forcing result onto recursion
+        if prolog.engine.ask_truthTO(engine_id, '''\
+                asserta(len([9, 81], 2+1)), len([27, 9, 81], 2), retract(len([9, 81], 2+1))
+                ;
+                asserta(len([9, 81], 1+2)), len([27, 9, 81], 2), retract(len([9, 81], 1+2))'''):
+            return [{'id': 'forcing_result_onto_recursion'}]
+
+        # same var on both sides of is
+        if prolog.engine.ask_truth(engine_id, 'len([], 0), \+ len([a, b, c], _)'):
+            return [{'id': 'same_var_on_both_sides_of_is'}]
 
         # base case works, the recursive doesn't (but it doesn't timeout)
         # this may be left as the last, most generic hint
diff --git a/prolog/problems/lists_advanced/len_2/sl.py b/prolog/problems/lists_advanced/len_2/sl.py
index 82c9d4b..e13ac3d 100644
--- a/prolog/problems/lists_advanced/len_2/sl.py
+++ b/prolog/problems/lists_advanced/len_2/sl.py
@@ -42,4 +42,28 @@ da je <code>X</code> hkrati starš in sestra od <code>Y</code> ali kaj podobno z
 <p>Je morda na delu potencialno neskončna rekurzija? Kako se bo ustavila?</p>
 <p>Morda pa je kriv tudi manjkajoč, neustrezen ali preprosto nekompatibilen (s splošnim primerom) robni pogoj?</p>
 ''',
+
+    'arbitrary_base_case': '''\
+<p>arbitrary_base_case</p>
+''',
+
+    'args_not_instantiated': '''\
+<p>args_not_instantiated</p>
+''',
+
+    '=_instead_of_is': '''\
+<p>=_instead_of_is</p>
+''',
+
+    '+H_instead_of_+1': '''\
+<p>+H_instead_of_+1</p>
+''',
+
+    'forcing_result_onto_recursion': '''\
+<p>forcing_result_onto_recursion</p>
+''',
+
+    'same_var_on_both_sides_of_is': '''\
+<p>same_var_on_both_sides_of_is</p>
+''',
 }
diff --git a/prolog/problems/lists_advanced/sum_2/common.py b/prolog/problems/lists_advanced/sum_2/common.py
index b3fa3bf..7d660d5 100644
--- a/prolog/problems/lists_advanced/sum_2/common.py
+++ b/prolog/problems/lists_advanced/sum_2/common.py
@@ -24,6 +24,12 @@ hint_type = {
     'base_case': Hint('base_case'),
     'recursive_case': Hint('recursive_case'),
     'timeout': Hint('timeout'),
+    'arbitrary_base_case': Hint('arbitrary_base_case'),
+    'args_not_instantiated': Hint('arbitrary_base_case'),
+    '=_instead_of_is': Hint('=_instead_of_is'),
+    '+1_instead_of_+H': Hint('+1_instead_of_+H'),
+    'forcing_result_onto_recursion': Hint('forcing_result_onto_recursion'),
+    'same_var_on_both_sides_of_is': Hint('same_var_on_both_sides_of_is'),
 }
 
 test_cases = [
@@ -68,13 +74,41 @@ def hint(code, aux_code):
             return [{'id': 'eq_instead_of_equ_markup', 'start': m[0], 'end': m[1]} for m in marks] + \
                    [{'id': 'eq_instead_of_equ'}]
 
+        # target predicate seems to always be false
+        if not prolog.engine.ask_truthTO(engine_id, 'sum(_, _)'):
+            return [{'id': 'predicate_always_false'}]
+
+        # arbitrary base case: len([], _)
+        if prolog.engine.ask_truthTO(engine_id, 'sum([], q), sum([], child(Q, q))'):
+            return [{'id': 'arbitrary_base_case'}]
+
         # missing/failed base case
         if not prolog.engine.ask_truthTO(engine_id, 'sum([], 0)'):
             return [{'id': 'base_case'}]
 
-        # target predicate seems to always be false
-        if not prolog.engine.ask_truthTO(engine_id, 'sum(_, _)'):
-            return [{'id': 'predicate_always_false'}]
+        # arguments not instantiated
+        reply, output = prolog.engine.ask(engine_id, 'sum([8, 12, -3], Sum)', timeout=1)
+        if reply.get('code') == 'instantiation_error':
+            return [{'id': 'args_not_instantiated'}]
+
+        # = instead of is
+        if prolog.engine.ask_truthTO(engine_id, 'sum([1, 3, 9, 27, 81], _+_)'):
+            return [{'id': '=_instead_of_is'}]
+
+        # +H instead of +1
+        if prolog.engine.ask_truthTO(engine_id, 'sum([1, 3, 9, 27, 81], 5)'):
+            return [{'id': '+H_instead_of_+1'}]
+
+        # forcing result onto recursion
+        if prolog.engine.ask_truthTO(engine_id, '''\
+                asserta(sum([9, 81], 90+27)), sum([27, 9, 81], 90), retract(sum([9, 81], 90+27))
+                ;
+                asserta(sum([9, 81], 27+90)), sum([27, 9, 81], 90), retract(sum([9, 81], 27+90))'''):
+            return [{'id': 'forcing_result_onto_recursion'}]
+
+        # same var on both sides of is
+        if prolog.engine.ask_truth(engine_id, 'sum([], 0), \+ sum([1, 3, 9], _)'):
+            return [{'id': 'same_var_on_both_sides_of_is'}]
 
         # base case works, the recursive doesn't (but it doesn't timeout)
         # this may be left as the last, most generic hint
diff --git a/prolog/problems/lists_advanced/sum_2/sl.py b/prolog/problems/lists_advanced/sum_2/sl.py
index f1094d3..a54c402 100644
--- a/prolog/problems/lists_advanced/sum_2/sl.py
+++ b/prolog/problems/lists_advanced/sum_2/sl.py
@@ -42,4 +42,28 @@ da je <code>X</code> hkrati starš in sestra od <code>Y</code> ali kaj podobno z
 <p>Je morda na delu potencialno neskončna rekurzija? Kako se bo ustavila?</p>
 <p>Morda pa je kriv tudi manjkajoč, neustrezen ali preprosto nekompatibilen (s splošnim primerom) robni pogoj?</p>
 ''',
+
+    'arbitrary_base_case': '''\
+<p>arbitrary_base_case</p>
+''',
+
+    'args_not_instantiated': '''\
+<p>args_not_instantiated</p>
+''',
+
+    '=_instead_of_is': '''\
+<p>=_instead_of_is</p>
+''',
+
+    '+H_instead_of_+1': '''\
+<p>+H_instead_of_+1</p>
+''',
+
+    'forcing_result_onto_recursion': '''\
+<p>forcing_result_onto_recursion</p>
+''',
+
+    'same_var_on_both_sides_of_is': '''\
+<p>same_var_on_both_sides_of_is</p>
+''',
 }