I can define and eval BNF definitions

tests/test_AddConceptEvaluator.py

@@ -8,9 +8,9 @@ from core.sheerka import Sheerka, ExecutionContext
 from core.tokenizer import Tokenizer
 from evaluators.AddConceptEvaluator import AddConceptEvaluator
 from parsers.BaseParser import BaseParser
-from parsers.ConceptLexerParser import Sequence, RegexParser, StrMatch, ZeroOrMore, ConceptMatch
+from parsers.ConceptLexerParser import Sequence, StrMatch, ZeroOrMore, ConceptMatch
+from parsers.BnfParser import BnfParser
 from parsers.DefaultParser import DefConceptNode, NameNode
-from parsers.ExactConceptParser import ExactConceptParser
 from parsers.PythonParser import PythonNode, PythonParser
 
 
@@ -67,7 +67,7 @@ def get_concept_definition(source, parsing_expression):
         status=True,
         value=ParserResultConcept(
             source=source,
-            parser=RegexParser(),
+            parser=BnfParser(),
             value=parsing_expression
         )
     )