anchor.diff:  :ASSERT_UNTIL^ LPARA! expression COMMA! expression RPARA! SEMICOL!
   ;
   
  -edge_expression
  -: POSEDGE^ ID
  +edge_statement
  +: WAIT_POSEDGE^ LPARA! expression RPARA! SEMICOL!
   ;
   assertStable_statement
   :ASSERT_STABLE^ LPARA! expression COMMA! expression RPARA! SEMICOL!
   ;
  +
  +
  +//waitPosedge_statement
  +//:WAIT_POSEDGE^ LPARA! expression RPARA! SEMICOL!
  +//;
   
   statement
   	:wait_statement
  
positive.code: 
  @header {
    package lpn.parser.properties;
    
   // package antlrPackage;
  }
  
  @lexer::header { 
  
negative.code: :'/'
  ;
  
  DASH
  :'***'
  ;
  EQUAL
  :'='
  ;
  