anchor.diff:    |  COLON
     ;
   
  -var_access :
  -     (name) (DOT name)*
  -  ;
  -
   literal :
        NUMBER
     |  STRING
  
positive.code:   ;
  
  pow_expr :
       (postfix_expr) ((MPOW | EPOW) postfix_expr)*
    ;
  
  postfix_expr :
       (primary_expr) (ARRAYTRANSPOSE | MTRANSPOSE)*
    ;
  
  primary_expr :
  
negative.code: 
  element_separator :
       COMMA
    ;
  
  input_params :
       LPAREN param_list? RPAREN
    ;
  
  param_list :
       name (COMMA name)*
    ;
  