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