?(?0 ()) (This example demonstrates how to implement combinatory calculus.) <> (M ?x) (?x ?x) <> (KI ?x ?y) (?y) <> (T ?x ?y) (?y ?y) <> (W ?x ?y) (?x ?y ?y) <> (K ?x ?y) (?x) <> (C ?x ?y ?z) (?x ?z ?y) <> (B ?x ?y ?z) (?x (?y ?z)) <> (I ?x) (?x) <> (S ?x ?y ?z) (?x ?z (?y ?z)) C KI x y z