anchor.diff:    | /* empty */
   ;
   
  +// induction clause
   induction_optional[ClawLanguage l]
     @init{
       List<String> temp = new ArrayList<>();
  
positive.code:   | /* empty */
  ;
  
  data_clause[ClawLanguage l]
    @init {
      List<String> temp = new ArrayList<>();
  
negative.code:  * This file is released under terms of BSD license
   * See LICENSE file for more information
   */
  
  /**
   * ANTLR 4 Grammar file for the CLAW directive language.
  