code: def p_let_arr_substr_in_args2(p):
      
      i = 2 if p[1].upper() == 'LET' else 1
  
      id_ = p[i]
      arg_list = p[i + 2]
      top_ = p[i + 5]
      substr = (make_number(0, lineno=p.lineno(i + 4)), top_)
      expr_ = p[i + 8]
      p[0] = make_array_substr_assign(p.lineno(i), id_, arg_list, substr, expr_)
docs: statement : LET ARRAY_ID LP arguments COMMA TO expr RP EQ expr
                    | ARRAY_ID LP arguments COMMA TO expr RP EQ expr