Alphabet
F
:
[a → a × a] ⟶ a → a
G
:
[a → a] ⟶ a → a
Variables
Z
:
a → a
U
:
a
Rules
F
(
F
(
Z
,
U
),
U
)
⇒
F
(
G
(
F
(
Z
,
U
)),
Z
·
U
)