意外的字符串相等结果

问：

我有一些 OCaml 代码：

let (&>) : ('x -> 'y) -> ('y -> 'z) -> ('x -> 'z) =
   fun g f x -> x |> g |> f

let soi x = string_of_int x
let sof x = string_of_float x
let fos x = float_of_string x
let ios x = int_of_string x

let clear_int = ios &> soi

let is_int_clear (x: string) = 
  let targ = clear_int x in
  let _ = print_endline x in
  let _ = print_endline targ in
  x == targ

let ccc = is_int_clear "123"

let scc = if ccc then "succ" else "fail"

let () = print_endline scc

我认为应该等于但输出这个："123""123"

123
123
fail

"123"是不平等的."123"

为什么以及如何解决它？