type WithoutImpl<T, U> =
  T extends [infer T1, ...infer T2]
  ? T1 extends U
    ? WithoutImpl<T2,U>
    : [T1, ...WithoutImpl<T2,U>]
  : []
type Without<T, U> =
  U extends readonly unknown[]
  ? WithoutImpl<T,U[number]>
  : WithoutImpl<T,U>

import type { Equal, Expect } from '@type-challenges/utils'

type cases = [
  Expect<Equal<Without<[1, 2], 1>, [2]>>,
  Expect<Equal<Without<[1, 2, 4, 1, 5], [1, 2]>, [4, 5]>>,
  Expect<Equal<Without<[2, 3, 2, 3, 2, 3, 2, 3], [2, 3]>, []>>,
]