anchor.diff:      ;
   
   variableDeclGroup
  -    :   VAR IDENTIFIER (COMMA IDENTIFIER)* COLON type SEMICOLON
  +    :   IDENTIFIER (COMMA IDENTIFIER)* COLON type
  +    ;
  +
  +variableDecl
  +    :   VAR variableDeclGroup SEMICOLON
       ;
   
   auxVariableDeclGroup
  -    :   AUX_VAR IDENTIFIER (COMMA IDENTIFIER)* COLON type SEMICOLON
  +    :   IDENTIFIER (COMMA IDENTIFIER)* COLON type
  +    ;
  +
  +auxVariableDecl
  +    :   AUX_VAR auxVariableDeclGroup SEMICOLON
       ;
   
   // state variable declaration
  
positive.code:     :   INITIALIZATION
          (affectsClause)*
          (facilityDecl)*
          (variableDeclGroup)*
          (auxVariableDeclGroup)*
          (stmt)*
          END SEMICOLON
      ;
  
negative.code:         (requiresClause)?
          (ensuresClause)?
          (facilityDecl)*
          (variableDecl)*
          (auxVariableDecl)*
          (stmt)*
          END SEMICOLON
      ;
  