Metamath Proof Explorer


Theorem cofuswapfcl

Description: The bifunctor pre-composed with a swap functor is a bifunctor. (Contributed by Zhi Wang, 10-Oct-2025)

Ref Expression
Hypotheses cofuswapf1.c φ C Cat
cofuswapf1.d φ D Cat
cofuswapf1.f φ F D × c C Func E
cofuswapf1.g No typesetting found for |- ( ph -> G = ( F o.func ( C swapF D ) ) ) with typecode |-
Assertion cofuswapfcl φ G C × c D Func E

Proof

Step Hyp Ref Expression
1 cofuswapf1.c φ C Cat
2 cofuswapf1.d φ D Cat
3 cofuswapf1.f φ F D × c C Func E
4 cofuswapf1.g Could not format ( ph -> G = ( F o.func ( C swapF D ) ) ) : No typesetting found for |- ( ph -> G = ( F o.func ( C swapF D ) ) ) with typecode |-
5 eqid C × c D = C × c D
6 eqid D × c C = D × c C
7 1 2 5 6 swapffunca Could not format ( ph -> ( C swapF D ) e. ( ( C Xc. D ) Func ( D Xc. C ) ) ) : No typesetting found for |- ( ph -> ( C swapF D ) e. ( ( C Xc. D ) Func ( D Xc. C ) ) ) with typecode |-
8 7 3 cofucl Could not format ( ph -> ( F o.func ( C swapF D ) ) e. ( ( C Xc. D ) Func E ) ) : No typesetting found for |- ( ph -> ( F o.func ( C swapF D ) ) e. ( ( C Xc. D ) Func E ) ) with typecode |-
9 4 8 eqeltrd φ G C × c D Func E