//@filename: file.tsx //@jsx: preserve declare module JSX { interface Element { isElement; } } var T: any, T1: any, T2: any; // This is an element var x1 = () => {}; x1.isElement; // This is a generic function var x2 = () => {}; x2(); // This is a generic function var x3 = () => {}; x3(); // This is an element var x4 = () => {}; x4.isElement; // This is an element var x5 = () => {}; x5.isElement;