=== tests/cases/compiler/inheritedFunctionAssignmentCompatibility.ts ===
interface IResultCallback extends Function { }
>IResultCallback : IResultCallback
>Function : Function

function fn(cb: IResultCallback) { }
>fn : (cb: IResultCallback) => void
>cb : IResultCallback
>IResultCallback : IResultCallback

fn((a, b) => true);
>fn((a, b) => true) : void
>fn : (cb: IResultCallback) => void
>(a, b) => true : (a: any, b: any) => boolean
>a : any
>b : any
>true : boolean

fn(function (a, b) { return true; })
>fn(function (a, b) { return true; }) : void
>fn : (cb: IResultCallback) => void
>function (a, b) { return true; } : (a: any, b: any) => boolean
>a : any
>b : any
>true : boolean