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Functor composition bifunctors
fuco2el
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fuco2eld
Metamath Proof Explorer
Ascii
Unicode
Theorem
fuco2el
Description:
Equivalence of product functor.
(Contributed by
Zhi Wang
, 29-Sep-2025)
Ref
Expression
Assertion
fuco2el
⊢
K
L
F
G
∈
S
×
R
↔
K
S
L
∧
F
R
G
Proof
Step
Hyp
Ref
Expression
1
opelxp
⊢
K
L
F
G
∈
S
×
R
↔
K
L
∈
S
∧
F
G
∈
R
2
df-br
⊢
K
S
L
↔
K
L
∈
S
3
df-br
⊢
F
R
G
↔
F
G
∈
R
4
2
3
anbi12i
⊢
K
S
L
∧
F
R
G
↔
K
L
∈
S
∧
F
G
∈
R
5
1
4
bitr4i
⊢
K
L
F
G
∈
S
×
R
↔
K
S
L
∧
F
R
G