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| Mirrors > Home > ILE Home > Th. List > isoeq2 | GIF version | ||
| Description: Equality theorem for isomorphisms. (Contributed by NM, 17-May-2004.) | 
| Ref | Expression | 
|---|---|
| isoeq2 | ⊢ (𝑅 = 𝑇 → (𝐻 Isom 𝑅, 𝑆 (𝐴, 𝐵) ↔ 𝐻 Isom 𝑇, 𝑆 (𝐴, 𝐵))) | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | breq 4035 | . . . . 5 ⊢ (𝑅 = 𝑇 → (𝑥𝑅𝑦 ↔ 𝑥𝑇𝑦)) | |
| 2 | 1 | bibi1d 233 | . . . 4 ⊢ (𝑅 = 𝑇 → ((𝑥𝑅𝑦 ↔ (𝐻‘𝑥)𝑆(𝐻‘𝑦)) ↔ (𝑥𝑇𝑦 ↔ (𝐻‘𝑥)𝑆(𝐻‘𝑦)))) | 
| 3 | 2 | 2ralbidv 2521 | . . 3 ⊢ (𝑅 = 𝑇 → (∀𝑥 ∈ 𝐴 ∀𝑦 ∈ 𝐴 (𝑥𝑅𝑦 ↔ (𝐻‘𝑥)𝑆(𝐻‘𝑦)) ↔ ∀𝑥 ∈ 𝐴 ∀𝑦 ∈ 𝐴 (𝑥𝑇𝑦 ↔ (𝐻‘𝑥)𝑆(𝐻‘𝑦)))) | 
| 4 | 3 | anbi2d 464 | . 2 ⊢ (𝑅 = 𝑇 → ((𝐻:𝐴–1-1-onto→𝐵 ∧ ∀𝑥 ∈ 𝐴 ∀𝑦 ∈ 𝐴 (𝑥𝑅𝑦 ↔ (𝐻‘𝑥)𝑆(𝐻‘𝑦))) ↔ (𝐻:𝐴–1-1-onto→𝐵 ∧ ∀𝑥 ∈ 𝐴 ∀𝑦 ∈ 𝐴 (𝑥𝑇𝑦 ↔ (𝐻‘𝑥)𝑆(𝐻‘𝑦))))) | 
| 5 | df-isom 5267 | . 2 ⊢ (𝐻 Isom 𝑅, 𝑆 (𝐴, 𝐵) ↔ (𝐻:𝐴–1-1-onto→𝐵 ∧ ∀𝑥 ∈ 𝐴 ∀𝑦 ∈ 𝐴 (𝑥𝑅𝑦 ↔ (𝐻‘𝑥)𝑆(𝐻‘𝑦)))) | |
| 6 | df-isom 5267 | . 2 ⊢ (𝐻 Isom 𝑇, 𝑆 (𝐴, 𝐵) ↔ (𝐻:𝐴–1-1-onto→𝐵 ∧ ∀𝑥 ∈ 𝐴 ∀𝑦 ∈ 𝐴 (𝑥𝑇𝑦 ↔ (𝐻‘𝑥)𝑆(𝐻‘𝑦)))) | |
| 7 | 4, 5, 6 | 3bitr4g 223 | 1 ⊢ (𝑅 = 𝑇 → (𝐻 Isom 𝑅, 𝑆 (𝐴, 𝐵) ↔ 𝐻 Isom 𝑇, 𝑆 (𝐴, 𝐵))) | 
| Colors of variables: wff set class | 
| Syntax hints: → wi 4 ∧ wa 104 ↔ wb 105 = wceq 1364 ∀wral 2475 class class class wbr 4033 –1-1-onto→wf1o 5257 ‘cfv 5258 Isom wiso 5259 | 
| This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-ia1 106 ax-ia2 107 ax-ia3 108 ax-5 1461 ax-gen 1463 ax-ie1 1507 ax-ie2 1508 ax-4 1524 ax-17 1540 ax-ial 1548 ax-ext 2178 | 
| This theorem depends on definitions: df-bi 117 df-nf 1475 df-cleq 2189 df-clel 2192 df-ral 2480 df-br 4034 df-isom 5267 | 
| This theorem is referenced by: (None) | 
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