Metamath Proof Explorer


Theorem grptcepi

Description: All morphisms in a category converted from a group are epimorphisms. (Contributed by Zhi Wang, 23-Sep-2024)

Ref Expression
Hypotheses grptcmon.c ( 𝜑𝐶 = ( MndToCat ‘ 𝐺 ) )
grptcmon.g ( 𝜑𝐺 ∈ Grp )
grptcmon.b ( 𝜑𝐵 = ( Base ‘ 𝐶 ) )
grptcmon.x ( 𝜑𝑋𝐵 )
grptcmon.y ( 𝜑𝑌𝐵 )
grptcmon.h ( 𝜑𝐻 = ( Hom ‘ 𝐶 ) )
grptcepi.e ( 𝜑𝐸 = ( Epi ‘ 𝐶 ) )
Assertion grptcepi ( 𝜑 → ( 𝑋 𝐸 𝑌 ) = ( 𝑋 𝐻 𝑌 ) )

Proof

Step Hyp Ref Expression
1 grptcmon.c ( 𝜑𝐶 = ( MndToCat ‘ 𝐺 ) )
2 grptcmon.g ( 𝜑𝐺 ∈ Grp )
3 grptcmon.b ( 𝜑𝐵 = ( Base ‘ 𝐶 ) )
4 grptcmon.x ( 𝜑𝑋𝐵 )
5 grptcmon.y ( 𝜑𝑌𝐵 )
6 grptcmon.h ( 𝜑𝐻 = ( Hom ‘ 𝐶 ) )
7 grptcepi.e ( 𝜑𝐸 = ( Epi ‘ 𝐶 ) )
8 eqid ( Base ‘ 𝐶 ) = ( Base ‘ 𝐶 )
9 eqid ( Hom ‘ 𝐶 ) = ( Hom ‘ 𝐶 )
10 eqid ( comp ‘ 𝐶 ) = ( comp ‘ 𝐶 )
11 eqid ( Epi ‘ 𝐶 ) = ( Epi ‘ 𝐶 )
12 2 grpmndd ( 𝜑𝐺 ∈ Mnd )
13 1 12 mndtccat ( 𝜑𝐶 ∈ Cat )
14 4 3 eleqtrd ( 𝜑𝑋 ∈ ( Base ‘ 𝐶 ) )
15 5 3 eleqtrd ( 𝜑𝑌 ∈ ( Base ‘ 𝐶 ) )
16 8 9 10 11 13 14 15 isepi2 ( 𝜑 → ( 𝑓 ∈ ( 𝑋 ( Epi ‘ 𝐶 ) 𝑌 ) ↔ ( 𝑓 ∈ ( 𝑋 ( Hom ‘ 𝐶 ) 𝑌 ) ∧ ∀ 𝑧 ∈ ( Base ‘ 𝐶 ) ∀ 𝑔 ∈ ( 𝑌 ( Hom ‘ 𝐶 ) 𝑧 ) ∀ ∈ ( 𝑌 ( Hom ‘ 𝐶 ) 𝑧 ) ( ( 𝑔 ( ⟨ 𝑋 , 𝑌 ⟩ ( comp ‘ 𝐶 ) 𝑧 ) 𝑓 ) = ( ( ⟨ 𝑋 , 𝑌 ⟩ ( comp ‘ 𝐶 ) 𝑧 ) 𝑓 ) → 𝑔 = ) ) ) )
17 1 ad2antrr ( ( ( 𝜑𝑓 ∈ ( 𝑋 ( Hom ‘ 𝐶 ) 𝑌 ) ) ∧ ( 𝑧 ∈ ( Base ‘ 𝐶 ) ∧ 𝑔 ∈ ( 𝑌 ( Hom ‘ 𝐶 ) 𝑧 ) ∧ ∈ ( 𝑌 ( Hom ‘ 𝐶 ) 𝑧 ) ) ) → 𝐶 = ( MndToCat ‘ 𝐺 ) )
18 12 ad2antrr ( ( ( 𝜑𝑓 ∈ ( 𝑋 ( Hom ‘ 𝐶 ) 𝑌 ) ) ∧ ( 𝑧 ∈ ( Base ‘ 𝐶 ) ∧ 𝑔 ∈ ( 𝑌 ( Hom ‘ 𝐶 ) 𝑧 ) ∧ ∈ ( 𝑌 ( Hom ‘ 𝐶 ) 𝑧 ) ) ) → 𝐺 ∈ Mnd )
19 3 ad2antrr ( ( ( 𝜑𝑓 ∈ ( 𝑋 ( Hom ‘ 𝐶 ) 𝑌 ) ) ∧ ( 𝑧 ∈ ( Base ‘ 𝐶 ) ∧ 𝑔 ∈ ( 𝑌 ( Hom ‘ 𝐶 ) 𝑧 ) ∧ ∈ ( 𝑌 ( Hom ‘ 𝐶 ) 𝑧 ) ) ) → 𝐵 = ( Base ‘ 𝐶 ) )
20 4 ad2antrr ( ( ( 𝜑𝑓 ∈ ( 𝑋 ( Hom ‘ 𝐶 ) 𝑌 ) ) ∧ ( 𝑧 ∈ ( Base ‘ 𝐶 ) ∧ 𝑔 ∈ ( 𝑌 ( Hom ‘ 𝐶 ) 𝑧 ) ∧ ∈ ( 𝑌 ( Hom ‘ 𝐶 ) 𝑧 ) ) ) → 𝑋𝐵 )
21 5 ad2antrr ( ( ( 𝜑𝑓 ∈ ( 𝑋 ( Hom ‘ 𝐶 ) 𝑌 ) ) ∧ ( 𝑧 ∈ ( Base ‘ 𝐶 ) ∧ 𝑔 ∈ ( 𝑌 ( Hom ‘ 𝐶 ) 𝑧 ) ∧ ∈ ( 𝑌 ( Hom ‘ 𝐶 ) 𝑧 ) ) ) → 𝑌𝐵 )
22 simpr1 ( ( ( 𝜑𝑓 ∈ ( 𝑋 ( Hom ‘ 𝐶 ) 𝑌 ) ) ∧ ( 𝑧 ∈ ( Base ‘ 𝐶 ) ∧ 𝑔 ∈ ( 𝑌 ( Hom ‘ 𝐶 ) 𝑧 ) ∧ ∈ ( 𝑌 ( Hom ‘ 𝐶 ) 𝑧 ) ) ) → 𝑧 ∈ ( Base ‘ 𝐶 ) )
23 22 19 eleqtrrd ( ( ( 𝜑𝑓 ∈ ( 𝑋 ( Hom ‘ 𝐶 ) 𝑌 ) ) ∧ ( 𝑧 ∈ ( Base ‘ 𝐶 ) ∧ 𝑔 ∈ ( 𝑌 ( Hom ‘ 𝐶 ) 𝑧 ) ∧ ∈ ( 𝑌 ( Hom ‘ 𝐶 ) 𝑧 ) ) ) → 𝑧𝐵 )
24 eqidd ( ( ( 𝜑𝑓 ∈ ( 𝑋 ( Hom ‘ 𝐶 ) 𝑌 ) ) ∧ ( 𝑧 ∈ ( Base ‘ 𝐶 ) ∧ 𝑔 ∈ ( 𝑌 ( Hom ‘ 𝐶 ) 𝑧 ) ∧ ∈ ( 𝑌 ( Hom ‘ 𝐶 ) 𝑧 ) ) ) → ( comp ‘ 𝐶 ) = ( comp ‘ 𝐶 ) )
25 eqidd ( ( ( 𝜑𝑓 ∈ ( 𝑋 ( Hom ‘ 𝐶 ) 𝑌 ) ) ∧ ( 𝑧 ∈ ( Base ‘ 𝐶 ) ∧ 𝑔 ∈ ( 𝑌 ( Hom ‘ 𝐶 ) 𝑧 ) ∧ ∈ ( 𝑌 ( Hom ‘ 𝐶 ) 𝑧 ) ) ) → ( ⟨ 𝑋 , 𝑌 ⟩ ( comp ‘ 𝐶 ) 𝑧 ) = ( ⟨ 𝑋 , 𝑌 ⟩ ( comp ‘ 𝐶 ) 𝑧 ) )
26 17 18 19 20 21 23 24 25 mndtcco2 ( ( ( 𝜑𝑓 ∈ ( 𝑋 ( Hom ‘ 𝐶 ) 𝑌 ) ) ∧ ( 𝑧 ∈ ( Base ‘ 𝐶 ) ∧ 𝑔 ∈ ( 𝑌 ( Hom ‘ 𝐶 ) 𝑧 ) ∧ ∈ ( 𝑌 ( Hom ‘ 𝐶 ) 𝑧 ) ) ) → ( 𝑔 ( ⟨ 𝑋 , 𝑌 ⟩ ( comp ‘ 𝐶 ) 𝑧 ) 𝑓 ) = ( 𝑔 ( +g𝐺 ) 𝑓 ) )
27 17 18 19 20 21 23 24 25 mndtcco2 ( ( ( 𝜑𝑓 ∈ ( 𝑋 ( Hom ‘ 𝐶 ) 𝑌 ) ) ∧ ( 𝑧 ∈ ( Base ‘ 𝐶 ) ∧ 𝑔 ∈ ( 𝑌 ( Hom ‘ 𝐶 ) 𝑧 ) ∧ ∈ ( 𝑌 ( Hom ‘ 𝐶 ) 𝑧 ) ) ) → ( ( ⟨ 𝑋 , 𝑌 ⟩ ( comp ‘ 𝐶 ) 𝑧 ) 𝑓 ) = ( ( +g𝐺 ) 𝑓 ) )
28 26 27 eqeq12d ( ( ( 𝜑𝑓 ∈ ( 𝑋 ( Hom ‘ 𝐶 ) 𝑌 ) ) ∧ ( 𝑧 ∈ ( Base ‘ 𝐶 ) ∧ 𝑔 ∈ ( 𝑌 ( Hom ‘ 𝐶 ) 𝑧 ) ∧ ∈ ( 𝑌 ( Hom ‘ 𝐶 ) 𝑧 ) ) ) → ( ( 𝑔 ( ⟨ 𝑋 , 𝑌 ⟩ ( comp ‘ 𝐶 ) 𝑧 ) 𝑓 ) = ( ( ⟨ 𝑋 , 𝑌 ⟩ ( comp ‘ 𝐶 ) 𝑧 ) 𝑓 ) ↔ ( 𝑔 ( +g𝐺 ) 𝑓 ) = ( ( +g𝐺 ) 𝑓 ) ) )
29 2 ad2antrr ( ( ( 𝜑𝑓 ∈ ( 𝑋 ( Hom ‘ 𝐶 ) 𝑌 ) ) ∧ ( 𝑧 ∈ ( Base ‘ 𝐶 ) ∧ 𝑔 ∈ ( 𝑌 ( Hom ‘ 𝐶 ) 𝑧 ) ∧ ∈ ( 𝑌 ( Hom ‘ 𝐶 ) 𝑧 ) ) ) → 𝐺 ∈ Grp )
30 simpr2 ( ( ( 𝜑𝑓 ∈ ( 𝑋 ( Hom ‘ 𝐶 ) 𝑌 ) ) ∧ ( 𝑧 ∈ ( Base ‘ 𝐶 ) ∧ 𝑔 ∈ ( 𝑌 ( Hom ‘ 𝐶 ) 𝑧 ) ∧ ∈ ( 𝑌 ( Hom ‘ 𝐶 ) 𝑧 ) ) ) → 𝑔 ∈ ( 𝑌 ( Hom ‘ 𝐶 ) 𝑧 ) )
31 eqidd ( ( ( 𝜑𝑓 ∈ ( 𝑋 ( Hom ‘ 𝐶 ) 𝑌 ) ) ∧ ( 𝑧 ∈ ( Base ‘ 𝐶 ) ∧ 𝑔 ∈ ( 𝑌 ( Hom ‘ 𝐶 ) 𝑧 ) ∧ ∈ ( 𝑌 ( Hom ‘ 𝐶 ) 𝑧 ) ) ) → ( Hom ‘ 𝐶 ) = ( Hom ‘ 𝐶 ) )
32 17 18 19 21 23 31 mndtchom ( ( ( 𝜑𝑓 ∈ ( 𝑋 ( Hom ‘ 𝐶 ) 𝑌 ) ) ∧ ( 𝑧 ∈ ( Base ‘ 𝐶 ) ∧ 𝑔 ∈ ( 𝑌 ( Hom ‘ 𝐶 ) 𝑧 ) ∧ ∈ ( 𝑌 ( Hom ‘ 𝐶 ) 𝑧 ) ) ) → ( 𝑌 ( Hom ‘ 𝐶 ) 𝑧 ) = ( Base ‘ 𝐺 ) )
33 30 32 eleqtrd ( ( ( 𝜑𝑓 ∈ ( 𝑋 ( Hom ‘ 𝐶 ) 𝑌 ) ) ∧ ( 𝑧 ∈ ( Base ‘ 𝐶 ) ∧ 𝑔 ∈ ( 𝑌 ( Hom ‘ 𝐶 ) 𝑧 ) ∧ ∈ ( 𝑌 ( Hom ‘ 𝐶 ) 𝑧 ) ) ) → 𝑔 ∈ ( Base ‘ 𝐺 ) )
34 simpr3 ( ( ( 𝜑𝑓 ∈ ( 𝑋 ( Hom ‘ 𝐶 ) 𝑌 ) ) ∧ ( 𝑧 ∈ ( Base ‘ 𝐶 ) ∧ 𝑔 ∈ ( 𝑌 ( Hom ‘ 𝐶 ) 𝑧 ) ∧ ∈ ( 𝑌 ( Hom ‘ 𝐶 ) 𝑧 ) ) ) → ∈ ( 𝑌 ( Hom ‘ 𝐶 ) 𝑧 ) )
35 34 32 eleqtrd ( ( ( 𝜑𝑓 ∈ ( 𝑋 ( Hom ‘ 𝐶 ) 𝑌 ) ) ∧ ( 𝑧 ∈ ( Base ‘ 𝐶 ) ∧ 𝑔 ∈ ( 𝑌 ( Hom ‘ 𝐶 ) 𝑧 ) ∧ ∈ ( 𝑌 ( Hom ‘ 𝐶 ) 𝑧 ) ) ) → ∈ ( Base ‘ 𝐺 ) )
36 simplr ( ( ( 𝜑𝑓 ∈ ( 𝑋 ( Hom ‘ 𝐶 ) 𝑌 ) ) ∧ ( 𝑧 ∈ ( Base ‘ 𝐶 ) ∧ 𝑔 ∈ ( 𝑌 ( Hom ‘ 𝐶 ) 𝑧 ) ∧ ∈ ( 𝑌 ( Hom ‘ 𝐶 ) 𝑧 ) ) ) → 𝑓 ∈ ( 𝑋 ( Hom ‘ 𝐶 ) 𝑌 ) )
37 17 18 19 20 21 31 mndtchom ( ( ( 𝜑𝑓 ∈ ( 𝑋 ( Hom ‘ 𝐶 ) 𝑌 ) ) ∧ ( 𝑧 ∈ ( Base ‘ 𝐶 ) ∧ 𝑔 ∈ ( 𝑌 ( Hom ‘ 𝐶 ) 𝑧 ) ∧ ∈ ( 𝑌 ( Hom ‘ 𝐶 ) 𝑧 ) ) ) → ( 𝑋 ( Hom ‘ 𝐶 ) 𝑌 ) = ( Base ‘ 𝐺 ) )
38 36 37 eleqtrd ( ( ( 𝜑𝑓 ∈ ( 𝑋 ( Hom ‘ 𝐶 ) 𝑌 ) ) ∧ ( 𝑧 ∈ ( Base ‘ 𝐶 ) ∧ 𝑔 ∈ ( 𝑌 ( Hom ‘ 𝐶 ) 𝑧 ) ∧ ∈ ( 𝑌 ( Hom ‘ 𝐶 ) 𝑧 ) ) ) → 𝑓 ∈ ( Base ‘ 𝐺 ) )
39 eqid ( Base ‘ 𝐺 ) = ( Base ‘ 𝐺 )
40 eqid ( +g𝐺 ) = ( +g𝐺 )
41 39 40 grprcan ( ( 𝐺 ∈ Grp ∧ ( 𝑔 ∈ ( Base ‘ 𝐺 ) ∧ ∈ ( Base ‘ 𝐺 ) ∧ 𝑓 ∈ ( Base ‘ 𝐺 ) ) ) → ( ( 𝑔 ( +g𝐺 ) 𝑓 ) = ( ( +g𝐺 ) 𝑓 ) ↔ 𝑔 = ) )
42 29 33 35 38 41 syl13anc ( ( ( 𝜑𝑓 ∈ ( 𝑋 ( Hom ‘ 𝐶 ) 𝑌 ) ) ∧ ( 𝑧 ∈ ( Base ‘ 𝐶 ) ∧ 𝑔 ∈ ( 𝑌 ( Hom ‘ 𝐶 ) 𝑧 ) ∧ ∈ ( 𝑌 ( Hom ‘ 𝐶 ) 𝑧 ) ) ) → ( ( 𝑔 ( +g𝐺 ) 𝑓 ) = ( ( +g𝐺 ) 𝑓 ) ↔ 𝑔 = ) )
43 28 42 bitrd ( ( ( 𝜑𝑓 ∈ ( 𝑋 ( Hom ‘ 𝐶 ) 𝑌 ) ) ∧ ( 𝑧 ∈ ( Base ‘ 𝐶 ) ∧ 𝑔 ∈ ( 𝑌 ( Hom ‘ 𝐶 ) 𝑧 ) ∧ ∈ ( 𝑌 ( Hom ‘ 𝐶 ) 𝑧 ) ) ) → ( ( 𝑔 ( ⟨ 𝑋 , 𝑌 ⟩ ( comp ‘ 𝐶 ) 𝑧 ) 𝑓 ) = ( ( ⟨ 𝑋 , 𝑌 ⟩ ( comp ‘ 𝐶 ) 𝑧 ) 𝑓 ) ↔ 𝑔 = ) )
44 43 biimpd ( ( ( 𝜑𝑓 ∈ ( 𝑋 ( Hom ‘ 𝐶 ) 𝑌 ) ) ∧ ( 𝑧 ∈ ( Base ‘ 𝐶 ) ∧ 𝑔 ∈ ( 𝑌 ( Hom ‘ 𝐶 ) 𝑧 ) ∧ ∈ ( 𝑌 ( Hom ‘ 𝐶 ) 𝑧 ) ) ) → ( ( 𝑔 ( ⟨ 𝑋 , 𝑌 ⟩ ( comp ‘ 𝐶 ) 𝑧 ) 𝑓 ) = ( ( ⟨ 𝑋 , 𝑌 ⟩ ( comp ‘ 𝐶 ) 𝑧 ) 𝑓 ) → 𝑔 = ) )
45 44 ralrimivvva ( ( 𝜑𝑓 ∈ ( 𝑋 ( Hom ‘ 𝐶 ) 𝑌 ) ) → ∀ 𝑧 ∈ ( Base ‘ 𝐶 ) ∀ 𝑔 ∈ ( 𝑌 ( Hom ‘ 𝐶 ) 𝑧 ) ∀ ∈ ( 𝑌 ( Hom ‘ 𝐶 ) 𝑧 ) ( ( 𝑔 ( ⟨ 𝑋 , 𝑌 ⟩ ( comp ‘ 𝐶 ) 𝑧 ) 𝑓 ) = ( ( ⟨ 𝑋 , 𝑌 ⟩ ( comp ‘ 𝐶 ) 𝑧 ) 𝑓 ) → 𝑔 = ) )
46 16 45 mpbiran3d ( 𝜑 → ( 𝑓 ∈ ( 𝑋 ( Epi ‘ 𝐶 ) 𝑌 ) ↔ 𝑓 ∈ ( 𝑋 ( Hom ‘ 𝐶 ) 𝑌 ) ) )
47 46 eqrdv ( 𝜑 → ( 𝑋 ( Epi ‘ 𝐶 ) 𝑌 ) = ( 𝑋 ( Hom ‘ 𝐶 ) 𝑌 ) )
48 7 oveqd ( 𝜑 → ( 𝑋 𝐸 𝑌 ) = ( 𝑋 ( Epi ‘ 𝐶 ) 𝑌 ) )
49 6 oveqd ( 𝜑 → ( 𝑋 𝐻 𝑌 ) = ( 𝑋 ( Hom ‘ 𝐶 ) 𝑌 ) )
50 47 48 49 3eqtr4d ( 𝜑 → ( 𝑋 𝐸 𝑌 ) = ( 𝑋 𝐻 𝑌 ) )