type Operation = (a: number, b: number) => number;
const add: Operation = (a, b) => a + b;
const sub: Operation = (a, b) => a - b;
const multiply: Operation = (a, b) => a / b;
type Operation2 = {
(a:number, b: number): number;
}
const add2: Operation2 = (a, b) => a + b;
const sub2: Operation2 = (a, b) => a - b;
const multiply2: Operation2 = (a, b) => a / b;