Function fib3

test/README.example.spec.ts:1381–1384

(n: number)

    };

    const fib3 = (n: number): Effected<never, number> => {
      if (n <= 1) return Effected.from(() => n);
      return fib3(n - 1).andThen((a) => fib3(n - 2).andThen((b) => a + b));
    };

    const fib4 = (n: number): Effected<never, number> => {
      if (n <= 1) return Effected.of(n);