Proof of Theorem mrefg2
| Step | Hyp | Ref | Expression | 
|---|
| 1 |  | isnacs.f | . . . . . . . . 9
⊢ 𝐹 = (mrCls‘𝐶) | 
| 2 | 1 | mrcssid 17661 | . . . . . . . 8
⊢ ((𝐶 ∈ (Moore‘𝑋) ∧ 𝑔 ⊆ 𝑋) → 𝑔 ⊆ (𝐹‘𝑔)) | 
| 3 |  | simpr 484 | . . . . . . . . 9
⊢ ((𝐶 ∈ (Moore‘𝑋) ∧ 𝑔 ⊆ (𝐹‘𝑔)) → 𝑔 ⊆ (𝐹‘𝑔)) | 
| 4 | 1 | mrcssv 17658 | . . . . . . . . . 10
⊢ (𝐶 ∈ (Moore‘𝑋) → (𝐹‘𝑔) ⊆ 𝑋) | 
| 5 | 4 | adantr 480 | . . . . . . . . 9
⊢ ((𝐶 ∈ (Moore‘𝑋) ∧ 𝑔 ⊆ (𝐹‘𝑔)) → (𝐹‘𝑔) ⊆ 𝑋) | 
| 6 | 3, 5 | sstrd 3993 | . . . . . . . 8
⊢ ((𝐶 ∈ (Moore‘𝑋) ∧ 𝑔 ⊆ (𝐹‘𝑔)) → 𝑔 ⊆ 𝑋) | 
| 7 | 2, 6 | impbida 800 | . . . . . . 7
⊢ (𝐶 ∈ (Moore‘𝑋) → (𝑔 ⊆ 𝑋 ↔ 𝑔 ⊆ (𝐹‘𝑔))) | 
| 8 |  | vex 3483 | . . . . . . . 8
⊢ 𝑔 ∈ V | 
| 9 | 8 | elpw 4603 | . . . . . . 7
⊢ (𝑔 ∈ 𝒫 𝑋 ↔ 𝑔 ⊆ 𝑋) | 
| 10 | 8 | elpw 4603 | . . . . . . 7
⊢ (𝑔 ∈ 𝒫 (𝐹‘𝑔) ↔ 𝑔 ⊆ (𝐹‘𝑔)) | 
| 11 | 7, 9, 10 | 3bitr4g 314 | . . . . . 6
⊢ (𝐶 ∈ (Moore‘𝑋) → (𝑔 ∈ 𝒫 𝑋 ↔ 𝑔 ∈ 𝒫 (𝐹‘𝑔))) | 
| 12 | 11 | anbi1d 631 | . . . . 5
⊢ (𝐶 ∈ (Moore‘𝑋) → ((𝑔 ∈ 𝒫 𝑋 ∧ 𝑔 ∈ Fin) ↔ (𝑔 ∈ 𝒫 (𝐹‘𝑔) ∧ 𝑔 ∈ Fin))) | 
| 13 |  | elin 3966 | . . . . 5
⊢ (𝑔 ∈ (𝒫 𝑋 ∩ Fin) ↔ (𝑔 ∈ 𝒫 𝑋 ∧ 𝑔 ∈ Fin)) | 
| 14 |  | elin 3966 | . . . . 5
⊢ (𝑔 ∈ (𝒫 (𝐹‘𝑔) ∩ Fin) ↔ (𝑔 ∈ 𝒫 (𝐹‘𝑔) ∧ 𝑔 ∈ Fin)) | 
| 15 | 12, 13, 14 | 3bitr4g 314 | . . . 4
⊢ (𝐶 ∈ (Moore‘𝑋) → (𝑔 ∈ (𝒫 𝑋 ∩ Fin) ↔ 𝑔 ∈ (𝒫 (𝐹‘𝑔) ∩ Fin))) | 
| 16 |  | pweq 4613 | . . . . . . 7
⊢ (𝑆 = (𝐹‘𝑔) → 𝒫 𝑆 = 𝒫 (𝐹‘𝑔)) | 
| 17 | 16 | ineq1d 4218 | . . . . . 6
⊢ (𝑆 = (𝐹‘𝑔) → (𝒫 𝑆 ∩ Fin) = (𝒫 (𝐹‘𝑔) ∩ Fin)) | 
| 18 | 17 | eleq2d 2826 | . . . . 5
⊢ (𝑆 = (𝐹‘𝑔) → (𝑔 ∈ (𝒫 𝑆 ∩ Fin) ↔ 𝑔 ∈ (𝒫 (𝐹‘𝑔) ∩ Fin))) | 
| 19 | 18 | bibi2d 342 | . . . 4
⊢ (𝑆 = (𝐹‘𝑔) → ((𝑔 ∈ (𝒫 𝑋 ∩ Fin) ↔ 𝑔 ∈ (𝒫 𝑆 ∩ Fin)) ↔ (𝑔 ∈ (𝒫 𝑋 ∩ Fin) ↔ 𝑔 ∈ (𝒫 (𝐹‘𝑔) ∩ Fin)))) | 
| 20 | 15, 19 | syl5ibrcom 247 | . . 3
⊢ (𝐶 ∈ (Moore‘𝑋) → (𝑆 = (𝐹‘𝑔) → (𝑔 ∈ (𝒫 𝑋 ∩ Fin) ↔ 𝑔 ∈ (𝒫 𝑆 ∩ Fin)))) | 
| 21 | 20 | pm5.32rd 578 | . 2
⊢ (𝐶 ∈ (Moore‘𝑋) → ((𝑔 ∈ (𝒫 𝑋 ∩ Fin) ∧ 𝑆 = (𝐹‘𝑔)) ↔ (𝑔 ∈ (𝒫 𝑆 ∩ Fin) ∧ 𝑆 = (𝐹‘𝑔)))) | 
| 22 | 21 | rexbidv2 3174 | 1
⊢ (𝐶 ∈ (Moore‘𝑋) → (∃𝑔 ∈ (𝒫 𝑋 ∩ Fin)𝑆 = (𝐹‘𝑔) ↔ ∃𝑔 ∈ (𝒫 𝑆 ∩ Fin)𝑆 = (𝐹‘𝑔))) |