code: def p_expression_uand(self, p):
          'expression : AND expression %prec UAND'
          p[0] = Uand(p[2], lineno=p.lineno(1))
          p.set_lineno(0, p.lineno(1)f p_expression_uand(self, p):
          'expression : AND expression %prec UAND'
          p[0] = Uand(p[2], lineno=p.lineno(1))
          p.set_lineno(0, p.lineno(1))
docs: expression : AND expression %prec UAND