Resolved some remaining chicken and egg when parsing BNF nodes

tests/core/test_SheerkaSetsManager.py

@@ -250,6 +250,40 @@ class TestSheerkaSetsManager(TestUsingMemoryBasedSheerka):
         assert sheerka.isa(bar, baz)
         assert sheerka.isa(foo, baz)
 
+    def test_concept_expression_recurse_id_is_updated(self):
+        sheerka, context, one, number, twenties = self.init_concepts(
+            "one",
+            "number",
+            Concept("twenties", definition="'twenty' number").def_var("number"),
+            create_new=True
+        )
+
+        assert twenties.bnf.elements[1].recurse_id is None
+
+        # update number
+        sheerka.set_isa(context, sheerka.new("one"), number)
+
+        assert twenties.bnf.elements[1].recurse_id == "1002#number#1003"
+
+    def test_concepts_in_group_cache_is_updated(self):
+        sheerka, context, one, two, number = self.init_concepts("one", "two", "number")
+
+        sheerka.set_isa(context, sheerka.new("one"), number)
+
+        elements = sheerka.get_set_elements(context, number)
+        assert [c.id for c in elements] == [one.id]
+
+        concepts_in_cache = sheerka.cache_manager.get(SheerkaSetsManager.CONCEPTS_IN_GROUPS_ENTRY, number.id)
+        assert [c.id for c in concepts_in_cache] == [one.id]
+
+        # add another element to number
+        sheerka.set_isa(context, sheerka.new("two"), number)
+        elements = sheerka.get_set_elements(context, number)
+        assert {c.id for c in elements} == {one.id, two.id}
+
+        concepts_in_cache = sheerka.cache_manager.get(SheerkaSetsManager.CONCEPTS_IN_GROUPS_ENTRY, number.id)
+        assert {c.id for c in concepts_in_cache} == {one.id, two.id}
+
 
 class TestSheerkaSetsManagerUsingFileBasedSheerka(TestUsingFileBasedSheerka):
     def test_i_can_add_concept_to_set_and_retrieve_it_in_another_session(self):
@@ -280,7 +314,7 @@ class TestSheerkaSetsManagerUsingFileBasedSheerka(TestUsingFileBasedSheerka):
         foo4 = Concept("foo4")
         for c in [foo3, foo4]:
             sheerka.create_new_concept(context, c)
-        
+
         sets_handler = sheerka.services[SheerkaSetsManager.NAME]
         res = sets_handler.add_concepts_to_set(context, (foo3, foo4), group)
         assert res.status