anchor.diff:  CONST: 'const';
   VAR: 'var';
   PROC: 'proc';
  +END_PROC: 'end_p';
   CPROC: 'cproc';
   IMPORT: 'import';
   INCLUDE: 'include';
  
positive.code: BAND: '&';
  OR: 'or';
  AND: 'and';
  XOR: 'xor'; // only binary
  EQUALS: '==';
  NOT_EQ: '!=';
  ASSIGN: '=';
  
negative.code: STATIC_IF: 'static_if';
  THEN: 'then';
  ELSE: 'else';
  ENDIF: 'end_if';
  UNIT: 'unit';
  PLUS: '+';
  MINUS: '-';
  