typeNamedUndefined2.ts(4,21): error TS2457: Type alias name cannot be 'undefined'.
typeNamedUndefined2.ts(17,17): error TS2457: Type alias name cannot be 'undefined'.


==== typeNamedUndefined2.ts (2 errors) ====
    export namespace ns {
        export namespace undefined {
            export const s = Symbol();
            export type undefined = typeof s;
                        ~~~~~~~~~
!!! error TS2457: Type alias name cannot be 'undefined'.
        };
        export function x(p: undefined): undefined {
            return p;
        }
    }
    
    export function x(p: ns.undefined.undefined) {
        return p;
    }
    
    export namespace undefined {
        export const s = Symbol();
        export type undefined = typeof s;
                    ~~~~~~~~~
!!! error TS2457: Type alias name cannot be 'undefined'.
    };
    