Nullable types helper (very short ^_^) for TypeScript

Nullable.ts

export type N<T> = T | null;
export type NU<T> = T extends undefined ? never : T;
export type NN<T> = NonNullable<T>;


//SAMPLE USE CASES
interface  TryNull{ 
    nullable: N<number>;
    maybe?: string;
    flag?: N<boolean>;
    same: { is: "same", type: "NON nullable" }
}

type TSame = TryNull['same'] // { is: "same", type: "NON nullable" }
type ns = N<TSame>    // null | { is: "same", type: "NON nullable" }
type is = NU<TSame>   // { is: "same", type: "NON nullable" }
type ok = NN<TSame>   // { is: "same", type: "NON nullable" }
type TFlag = TryNull['flag'];   // boolean | null | undefined
type b = NN<TFlag>;             // boolean
type bn = NU<TFlag>;            // boolean | null
type ss = NU<TryNull['maybe']>; // string
type ts = NU<TryNull['maybe']>; // string
type tn = NN<TryNull['nullable']>; //number