anchor.diff:                       |  TOKPERCENT  nterm<<V>>
                        )*                   {{ return v }}
   
  -    rule fieldname: VAR
  -
       rule nterm<<V>>:
           [ (TOKEXCLAIM | TOKTILDE | TOKMINUS ) ] term<<V>> {{ return term }}
   
  
positive.code:         ( EQUAL | LARROW ) assign_value SEMICOLON
  
      rule module_param:
          #Type_nitem [ VAR ] [ STAR ]
          Type_nitem [ VAR | STAR ]
  
      rule module_declaration:
  
negative.code:     rule term<<V>>:
          term_partial<<V>>
          ( LBRACKET expr<<V>> [ COLON expr<<V>> ] RBRACKET
          | DOT VAR [ call_params ]
          )*
          {{ return term_partial }}
  
  