anchor.diff:  	;
   
   entity_expr
  -	: single_valued_association_path_expression
  -	| simple_entity_expression;
  -
  -simple_entity_expression
  -	: identification_variable
  +	: single_valued_association_path_expr
  +	| simple_entity_expr;
  +
  +simple_entity_expr
  +	: identification_var
   	;
   
   functions_returning_numerics
  
positive.code: 	;
  
  simple_arithmetic_expr
  	: arithmetic_term
  	| simple_arithmetic_expr ( '+' | '-' ) arithmetic_term;
  
  arithmetic_term
  	: arithmetic_factor
  	| arithmetic_term ( '*' | '/' ) arithmetic_factor;
  
  arithmetic_factor
  	: ( '+' | '-' )? arithmetic_primary;
  
negative.code: in_stmt	: column[null] keyIN LPAREN qstring_list RPAREN;
  
  cond_expr
  	: cond_term (keyOR cond_expr)?
  	//| cond_expr keyOR cond_term
  	;
  
  cond_term
  	: cond_factor (keyAND cond_term)?
  	//| cond_term keyAND cond_factor
  	;
  	
  cond_factor
  	: (keyNOT)? cond_primary;
  
  cond_primary
  	: simple_cond_expr 
  	| LPAREN cond_expr RPAREN
  	;
  
  simple_cond_expr
  	: comp_expr
  	| between_expr
  	| like_expr
  	| in_expression
  	| null_comparison_expr
  	| empty_collection_comp_expr
  	| collection_member_expr
  	;
  
  