Fixed #131 : Implement ExprToConditions

Fixed #130 : ArithmeticOperatorParser
Fixed #129 : python_wrapper : create_namespace
Fixed #128 : ExpressionParser: Cannot parse func(x) infixed concept 'xxx'

tests/non_reg/test_sheerka_non_reg.py

@@ -661,7 +661,6 @@ as:
         ]
 
         sheerka = self.init_scenario(init, global_truth=True)
-        context = self.get_context(sheerka)
 
         res = sheerka.evaluate_user_input("twenty one")
         assert len(res) == 1

tests/non_reg/test_sheerka_non_reg_pipe_functions.py

@@ -69,9 +69,9 @@ class TestSheerkaNonRegPipeFunctions(TestUsingMemoryBasedSheerka):
     def test_i_can_collect_properties(self):
         init = [
             "def concept one as 1",
-            "def concept isa from x is a y def_var x def_var y",
+            "def concept is_a from x is a y def_var x def_var y",
             "def concept plus from a plus b as a + b",
-            "add_to_memory('x', [one, isa, plus])"
+            "add_to_memory('x', [one, is_a, plus])"
         ]
 
         sheerka = self.init_scenario(init)
@@ -80,6 +80,6 @@ class TestSheerkaNonRegPipeFunctions(TestUsingMemoryBasedSheerka):
         assert len(res) == 1
         assert res[0].status
         assert sheerka.isinstance(res[0].body, BuiltinConcepts.TO_DICT)
-        assert res[0].body.body == {'isa': ['body', 'id', 'key', 'name', 'x', 'y'],
+        assert res[0].body.body == {'is_a': ['body', 'id', 'key', 'name', 'x', 'y'],
                                     'one': ['body', 'id', 'key', 'name'],
                                     'plus': ['a', 'b', 'body', 'id', 'key', 'name']}