interface Boolean {
    valueOf(): boolean;
    constructor: BooleanConstructor;
}
interface BooleanConstructor {
    (val: any): boolean;
    new (val: any): Boolean;
    prototype: Boolean;
}

declare var Boolean: BooleanConstructor;

gt.Boolean = function (this: Boolean | undefined, arg) {
    var val;
    if (arguments.length === 0) val = false;
    else val = !!arg;
    if (this === undefined || this === null) return val;
    else (this as any).value = val;
} as BooleanConstructor;

Boolean.prototype = (false as any).__proto__ as Boolean;
setConstr(Boolean.prototype, Boolean);