message: trace zipWith
diff: @@ -12,9 +12,11 @@ import { map_ } from "./map"
  */
  export function zipWith<A, R2, E2, A2, B>(
  b: Effect<R2, E2, A2>,
  - f: (a: A, b: A2) => B
  + f: (a: A, b: A2) => B,
  + __trace?: string
  ) {
  - return <R, E>(a: Effect<R, E, A>): Effect<R & R2, E | E2, B> => zipWith_(a, b, f)
  + return <R, E>(a: Effect<R, E, A>): Effect<R & R2, E | E2, B> =>
  + zipWith_(a, b, f, __trace)
  }
  /**
  @@ -24,7 +26,8 @@ export function zipWith<A, R2, E2, A2, B>(
  export function zipWith_<R, E, A, R2, E2, A2, B>(
  a: Effect<R, E, A>,
  b: Effect<R2, E2, A2>,
  - f: (a: A, b: A2) => B
  + f: (a: A, b: A2) => B,
  + __trace?: string
  ): Effect<R & R2, E | E2, B> {
  - return chain_(a, (ra) => map_(b, (rb) => f(ra, rb)))
  + return chain_(a, (ra) => map_(b, (rb) => f(ra, rb)), __trace)
  }
  