Alphabet

f:[d → d × b] ⟶ c
g:[b × a] ⟶ d → d
h:[a → b → c] ⟶ b
i:[c] ⟶ c

Variables

F:a → b → c
Y:a
U:b

Rules

f(g(h(F), Y), U)i(F · Y · U)