Metamath Proof Explorer


Theorem rngccofvalALTV

Description: Composition in the category of non-unital rings. (New usage is discouraged.) (Contributed by AV, 27-Feb-2020)

Ref Expression
Hypotheses rngcbasALTV.c C = RngCatALTV U
rngcbasALTV.b B = Base C
rngcbasALTV.u φ U V
rngccofvalALTV.o · ˙ = comp C
Assertion rngccofvalALTV φ · ˙ = v B × B , z B g 2 nd v RngHomo z , f 1 st v RngHomo 2 nd v g f

Proof

Step Hyp Ref Expression
1 rngcbasALTV.c C = RngCatALTV U
2 rngcbasALTV.b B = Base C
3 rngcbasALTV.u φ U V
4 rngccofvalALTV.o · ˙ = comp C
5 1 2 3 rngcbasALTV φ B = U Rng
6 eqid Hom C = Hom C
7 1 2 3 6 rngchomfvalALTV φ Hom C = x B , y B x RngHomo y
8 eqidd φ v B × B , z B g 2 nd v RngHomo z , f 1 st v RngHomo 2 nd v g f = v B × B , z B g 2 nd v RngHomo z , f 1 st v RngHomo 2 nd v g f
9 1 3 5 7 8 rngcvalALTV φ C = Base ndx B Hom ndx Hom C comp ndx v B × B , z B g 2 nd v RngHomo z , f 1 st v RngHomo 2 nd v g f
10 9 fveq2d φ comp C = comp Base ndx B Hom ndx Hom C comp ndx v B × B , z B g 2 nd v RngHomo z , f 1 st v RngHomo 2 nd v g f
11 2 fvexi B V
12 sqxpexg B V B × B V
13 11 12 ax-mp B × B V
14 13 11 mpoex v B × B , z B g 2 nd v RngHomo z , f 1 st v RngHomo 2 nd v g f V
15 catstr Base ndx B Hom ndx Hom C comp ndx v B × B , z B g 2 nd v RngHomo z , f 1 st v RngHomo 2 nd v g f Struct 1 15
16 ccoid comp = Slot comp ndx
17 snsstp3 comp ndx v B × B , z B g 2 nd v RngHomo z , f 1 st v RngHomo 2 nd v g f Base ndx B Hom ndx Hom C comp ndx v B × B , z B g 2 nd v RngHomo z , f 1 st v RngHomo 2 nd v g f
18 15 16 17 strfv v B × B , z B g 2 nd v RngHomo z , f 1 st v RngHomo 2 nd v g f V v B × B , z B g 2 nd v RngHomo z , f 1 st v RngHomo 2 nd v g f = comp Base ndx B Hom ndx Hom C comp ndx v B × B , z B g 2 nd v RngHomo z , f 1 st v RngHomo 2 nd v g f
19 14 18 ax-mp v B × B , z B g 2 nd v RngHomo z , f 1 st v RngHomo 2 nd v g f = comp Base ndx B Hom ndx Hom C comp ndx v B × B , z B g 2 nd v RngHomo z , f 1 st v RngHomo 2 nd v g f
20 10 4 19 3eqtr4g φ · ˙ = v B × B , z B g 2 nd v RngHomo z , f 1 st v RngHomo 2 nd v g f