A Tree that encapsulates Unification Algorithm, Backward Chaining and Backtracking.
- Internal nodes are ordered lists of subgoals
- Leaves are success nodes or failures
- Edges are labeled with variable bindings
Example
- male(charlie).
- male(bob).
- female(alice).
- female(eve).
- parent(charlie, bob).
- parent(eve, bob).
- parent(charlie, alice).
- parent(eve, alice).
- sibling(X,Y) :- parent(P,X), parent(P,Y).
Lets try:
sibling(alice, Who)