help with my predicate

[jodders]

heres a list of facts of some names,

king(Name,datefrom,dateto)

king('Bill',1864,1895). %predicates
king('Fred',1895,1901).
king('Joe',1901,1923).
king('Bob',1923,1930).
king('Charlie',1930,1946).

Im trying to write a predicate called ruled_after(X,Y) which is true when King X ruled at some later time than King Y.

Regards

 

[byleth]

rulled_after(X, Y) :-
king(X, F1, _), king(Y, _, T2),
F1 >= T2.


%i haven't tried it, but i guess it's just that..