login :- getdata(_, _), writeln('Welcome!'). login :- repeat, writeln('Sorry, you are not permitted.'), getdata(_, _), writeln('Welcome'). getdata(Name, Password) :- write('Username: '), read(Name), write('Password: '), read(Password), user(Name, Password). user(john, john1). user(jimmy, jimmy1). user(mary, mary1).