Metamath Proof Explorer


Theorem prcoftposcurfucoa

Description: The pre-composition functor is the transposed curry of the functor composition bifunctor. (Contributed by Zhi Wang, 2-Nov-2025)

Ref Expression
Hypotheses prcoffunc.r 𝑅 = ( 𝐷 FuncCat 𝐸 )
prcoffunc.e ( 𝜑𝐸 ∈ Cat )
prcoftposcurfuco.q 𝑄 = ( 𝐶 FuncCat 𝐷 )
prcoftposcurfuco.o ( 𝜑 = ( ⟨ 𝑄 , 𝑅 ⟩ curryF ( ( ⟨ 𝐶 , 𝐷 ⟩ ∘F 𝐸 ) ∘func ( 𝑄 swapF 𝑅 ) ) ) )
prcoftposcurfucoa.m ( 𝜑𝑀 = ( ( 1st ) ‘ 𝐹 ) )
prcoftposcurfucoa.f ( 𝜑𝐹 ∈ ( 𝐶 Func 𝐷 ) )
Assertion prcoftposcurfucoa ( 𝜑 → ( ⟨ 𝐷 , 𝐸 ⟩ −∘F 𝐹 ) = 𝑀 )

Proof

Step Hyp Ref Expression
1 prcoffunc.r 𝑅 = ( 𝐷 FuncCat 𝐸 )
2 prcoffunc.e ( 𝜑𝐸 ∈ Cat )
3 prcoftposcurfuco.q 𝑄 = ( 𝐶 FuncCat 𝐷 )
4 prcoftposcurfuco.o ( 𝜑 = ( ⟨ 𝑄 , 𝑅 ⟩ curryF ( ( ⟨ 𝐶 , 𝐷 ⟩ ∘F 𝐸 ) ∘func ( 𝑄 swapF 𝑅 ) ) ) )
5 prcoftposcurfucoa.m ( 𝜑𝑀 = ( ( 1st ) ‘ 𝐹 ) )
6 prcoftposcurfucoa.f ( 𝜑𝐹 ∈ ( 𝐶 Func 𝐷 ) )
7 relfunc Rel ( 𝐶 Func 𝐷 )
8 1st2nd ( ( Rel ( 𝐶 Func 𝐷 ) ∧ 𝐹 ∈ ( 𝐶 Func 𝐷 ) ) → 𝐹 = ⟨ ( 1st𝐹 ) , ( 2nd𝐹 ) ⟩ )
9 7 6 8 sylancr ( 𝜑𝐹 = ⟨ ( 1st𝐹 ) , ( 2nd𝐹 ) ⟩ )
10 9 oveq2d ( 𝜑 → ( ⟨ 𝐷 , 𝐸 ⟩ −∘F 𝐹 ) = ( ⟨ 𝐷 , 𝐸 ⟩ −∘F ⟨ ( 1st𝐹 ) , ( 2nd𝐹 ) ⟩ ) )
11 9 fveq2d ( 𝜑 → ( ( 1st ) ‘ 𝐹 ) = ( ( 1st ) ‘ ⟨ ( 1st𝐹 ) , ( 2nd𝐹 ) ⟩ ) )
12 5 11 eqtrd ( 𝜑𝑀 = ( ( 1st ) ‘ ⟨ ( 1st𝐹 ) , ( 2nd𝐹 ) ⟩ ) )
13 6 func1st2nd ( 𝜑 → ( 1st𝐹 ) ( 𝐶 Func 𝐷 ) ( 2nd𝐹 ) )
14 1 2 3 4 12 13 prcoftposcurfuco ( 𝜑 → ( ⟨ 𝐷 , 𝐸 ⟩ −∘F ⟨ ( 1st𝐹 ) , ( 2nd𝐹 ) ⟩ ) = 𝑀 )
15 10 14 eqtrd ( 𝜑 → ( ⟨ 𝐷 , 𝐸 ⟩ −∘F 𝐹 ) = 𝑀 )