(module
    (func $fac_rec (export "fac_rec") (param $n i64) (result i64)
        (if (result i64)
            (i64.eq
                (local.get $n)
                (i64.const 0)
            )
            (then
                (i64.const 1)
            )
            (else
                (i64.mul
                    (local.get $n)
                    (call $fac_rec
                        (i64.sub
                            (local.get $n)
                            (i64.const 1)
                        )
                    )
                )
            )
        )
    )
)