Define family relations

tp/1/parent.lp

@@ -0,0 +1,7 @@
+% Define
+parent(lucie,robert). parent(robert,mattis). parent(robert,anna).
+
+% Generate
+child(C, P) :- parent(P, C).
+grandparent(G, C) :- parent(G, P), parent(P, C).
+sibling(S1, S2) :- parent(P, S1), parent(P, S2), S1 > S2.