code: def p_elseif_part(p):
      
      if p[1] == 'ELSEIF':
          label_ = make_nop()  # No label
          cond_ = p[2]
      else:
          label_ = make_label(p[1], p.lineno(1))
          cond_ = p[3]
  
      p[0] = label_, cond_
docs: elseif_expr : ELSEIF expr then
                      | LABEL ELSEIF expr then