You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: powf64.rs
    path of file: ./repos/kani/tests/kani/Intrinsics/Math/Arith
    
    the code of the file until where you have to start completion: // Copyright Kani Contributors
// SPDX-License-Identifier: Apache-2.0 OR MIT
//
// This test will trigger use of the `powf64` intrinsic, which in turn invoke functions modelled in
// CBMC's math library. These models use approximations as documented in CBMC's source code:
// https://github.com/d
    
    fn verify_f() {
        const LIMIT: u64 = 10;
        let x: u64 = kani::any();
        let y: u64 = kani::any();
        // outside these limits our approximation may yield spurious results
        kani::assume(x > LIMIT && x < LIMIT * 3);
        kani::assume(y > LIMIT && y < LIMIT * 3);
        kani::assume(x > y);
        let x_ = f(x);
        let y_ = f(y);
        assert!(x_ >= y_);
    }