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Mirrors > Home > ILE Home > Th. List > ordeq | GIF version |
Description: Equality theorem for the ordinal predicate. (Contributed by NM, 17-Sep-1993.) |
Ref | Expression |
---|---|
ordeq | ⊢ (𝐴 = 𝐵 → (Ord 𝐴 ↔ Ord 𝐵)) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | treq 3881 | . . 3 ⊢ (𝐴 = 𝐵 → (Tr 𝐴 ↔ Tr 𝐵)) | |
2 | raleq 2549 | . . 3 ⊢ (𝐴 = 𝐵 → (∀𝑥 ∈ 𝐴 Tr 𝑥 ↔ ∀𝑥 ∈ 𝐵 Tr 𝑥)) | |
3 | 1, 2 | anbi12d 456 | . 2 ⊢ (𝐴 = 𝐵 → ((Tr 𝐴 ∧ ∀𝑥 ∈ 𝐴 Tr 𝑥) ↔ (Tr 𝐵 ∧ ∀𝑥 ∈ 𝐵 Tr 𝑥))) |
4 | dford3 4122 | . 2 ⊢ (Ord 𝐴 ↔ (Tr 𝐴 ∧ ∀𝑥 ∈ 𝐴 Tr 𝑥)) | |
5 | dford3 4122 | . 2 ⊢ (Ord 𝐵 ↔ (Tr 𝐵 ∧ ∀𝑥 ∈ 𝐵 Tr 𝑥)) | |
6 | 3, 4, 5 | 3bitr4g 221 | 1 ⊢ (𝐴 = 𝐵 → (Ord 𝐴 ↔ Ord 𝐵)) |
Colors of variables: wff set class |
Syntax hints: → wi 4 ∧ wa 102 ↔ wb 103 = wceq 1284 ∀wral 2348 Tr wtr 3875 Ord word 4117 |
This theorem was proved from axioms: ax-1 5 ax-2 6 ax-mp 7 ax-ia1 104 ax-ia2 105 ax-ia3 106 ax-io 662 ax-5 1376 ax-7 1377 ax-gen 1378 ax-ie1 1422 ax-ie2 1423 ax-8 1435 ax-10 1436 ax-11 1437 ax-i12 1438 ax-bndl 1439 ax-4 1440 ax-17 1459 ax-i9 1463 ax-ial 1467 ax-i5r 1468 ax-ext 2063 |
This theorem depends on definitions: df-bi 115 df-tru 1287 df-nf 1390 df-sb 1686 df-clab 2068 df-cleq 2074 df-clel 2077 df-nfc 2208 df-ral 2353 df-rex 2354 df-in 2979 df-ss 2986 df-uni 3602 df-tr 3876 df-iord 4121 |
This theorem is referenced by: elong 4128 limeq 4132 ordelord 4136 ordtriexmidlem 4263 2ordpr 4267 issmo 5926 issmo2 5927 smoeq 5928 smores 5930 smores2 5932 smodm2 5933 smoiso 5940 tfrlem8 5957 |
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