(\zero . \one . \two . \three . \succ . \plus . \mult . \pred . \minus . \isZero . insert_your_expression_here) (\f . \x . x) (\f . \x . f x) (\f . \x . f (f x)) (\f . \x . f (f (f x))) (\n . \f . \x . f (n f x)) (\m . \n . \f . \x . m f (n f x)) (\m . \n . \f . m (n f)) (\n . \f . \x . n (\g . \h . h (g f)) (\u . x) (\u . u)) (\m . \n . n (\n . \f . \x . n (\g . \h . h (g f)) (\u . x) (\u . u)) m) (\n . n (\x . \x . \y . y) (\x . \y . x))