export interface IxMonad<F> {
  readonly URI: F
  readonly iof: <I, A>(a: A) => HKT3<F, I, I, A>
  readonly ichain: <I, O, Z, A, B>(fa: HKT3<F, I, O, A>, f: (a: A) => HKT3<F, O, Z, B>) => HKT3<F, I, Z, B>
}

export interface IxMonad3<F extends URIS3> {
  readonly URI: F
  readonly iof: <I, A>(a: A) => Type3<F, I, I, A>
  readonly ichain: <I, O, Z, A, B>(fa: Type3<F, I, O, A>, f: (a: A) => Type3<F, O, Z, B>) => Type3<F, I, Z, B>
}

export function iapplyFirst<F extends URIS3>(
  ixmonad: IxMonad3<F>
): <I, O, A, Z, B>(fa: Type3<F, I, O, A>, fb: Type3<F, O, Z, B>) => Type3<F, I, Z, A>
export function iapplyFirst<F>(
  ixmonad: IxMonad<F>
): <I, O, A, Z, B>(fa: HKT3<F, I, O, A>, fb: HKT3<F, O, Z, B>) => HKT3<F, I, Z, A> { ... }

export function iapplySecond<F extends URIS3>(
  ixmonad: IxMonad3<F>
): <I, O, A, Z, B>(fa: Type3<F, I, O, A>, fb: Type3<F, O, Z, B>) => Type3<F, I, Z, B>
export function iapplySecond<F>(
  ixmonad: IxMonad<F>
): <I, O, A, Z, B>(fa: HKT3<F, I, O, A>, fb: HKT3<F, O, Z, B>) => HKT3<F, I, Z, B> { ... }