RosettaCodeData/Task/Mutual-recursion/Picat/mutual-recursion-2.picat

table
female(0,1).
female(N,F) :-
  N>0,
  N1 = N-1,
  female(N1,R),
  male(R, R1),
  F = N-R1.

table
male(0,0).
male(N,F) :-
  N>0,
  N1 = N-1,
  male(N1,R),
  female(R, R1),
  F = N-R1.