Metamath Proof Explorer


Theorem estrreslem2

Description: Lemma 2 for estrres . (Contributed by AV, 14-Mar-2020)

Ref Expression
Hypotheses estrres.c φ C = Base ndx B Hom ndx H comp ndx · ˙
estrres.b φ B V
estrres.h φ H X
estrres.x φ · ˙ Y
Assertion estrreslem2 φ Base ndx dom C

Proof

Step Hyp Ref Expression
1 estrres.c φ C = Base ndx B Hom ndx H comp ndx · ˙
2 estrres.b φ B V
3 estrres.h φ H X
4 estrres.x φ · ˙ Y
5 eqidd φ Base ndx = Base ndx
6 5 3mix1d φ Base ndx = Base ndx Base ndx = Hom ndx Base ndx = comp ndx
7 fvex Base ndx V
8 eltpg Base ndx V Base ndx Base ndx Hom ndx comp ndx Base ndx = Base ndx Base ndx = Hom ndx Base ndx = comp ndx
9 7 8 mp1i φ Base ndx Base ndx Hom ndx comp ndx Base ndx = Base ndx Base ndx = Hom ndx Base ndx = comp ndx
10 6 9 mpbird φ Base ndx Base ndx Hom ndx comp ndx
11 df-tp Base ndx B Hom ndx H comp ndx · ˙ = Base ndx B Hom ndx H comp ndx · ˙
12 11 a1i φ Base ndx B Hom ndx H comp ndx · ˙ = Base ndx B Hom ndx H comp ndx · ˙
13 12 dmeqd φ dom Base ndx B Hom ndx H comp ndx · ˙ = dom Base ndx B Hom ndx H comp ndx · ˙
14 dmun dom Base ndx B Hom ndx H comp ndx · ˙ = dom Base ndx B Hom ndx H dom comp ndx · ˙
15 14 a1i φ dom Base ndx B Hom ndx H comp ndx · ˙ = dom Base ndx B Hom ndx H dom comp ndx · ˙
16 dmpropg B V H X dom Base ndx B Hom ndx H = Base ndx Hom ndx
17 2 3 16 syl2anc φ dom Base ndx B Hom ndx H = Base ndx Hom ndx
18 dmsnopg · ˙ Y dom comp ndx · ˙ = comp ndx
19 4 18 syl φ dom comp ndx · ˙ = comp ndx
20 17 19 uneq12d φ dom Base ndx B Hom ndx H dom comp ndx · ˙ = Base ndx Hom ndx comp ndx
21 13 15 20 3eqtrd φ dom Base ndx B Hom ndx H comp ndx · ˙ = Base ndx Hom ndx comp ndx
22 1 dmeqd φ dom C = dom Base ndx B Hom ndx H comp ndx · ˙
23 df-tp Base ndx Hom ndx comp ndx = Base ndx Hom ndx comp ndx
24 23 a1i φ Base ndx Hom ndx comp ndx = Base ndx Hom ndx comp ndx
25 21 22 24 3eqtr4d φ dom C = Base ndx Hom ndx comp ndx
26 10 25 eleqtrrd φ Base ndx dom C