Intuitionistic Logic Explorer |
< Previous
Next >
Nearby theorems |
||
Mirrors > Home > ILE Home > Th. List > opexgOLD | GIF version |
Description: An ordered pair of sets is a set. This is a special case of opexg 3964 and new proofs should use opexg 3964 instead. (Contributed by Jim Kingdon, 19-Sep-2018.) (New usage is discouraged.) (Proof modification is discouraged.) TODO: replace its uses by uses of opexg 3964 and then remove it. |
Ref | Expression |
---|---|
opexgOLD | ⊢ ((𝐴 ∈ V ∧ 𝐵 ∈ V) → 〈𝐴, 𝐵〉 ∈ V) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | dfopg 3547 | . 2 ⊢ ((𝐴 ∈ V ∧ 𝐵 ∈ V) → 〈𝐴, 𝐵〉 = {{𝐴}, {𝐴, 𝐵}}) | |
2 | snexgOLD 3935 | . . . . 5 ⊢ (𝐴 ∈ V → {𝐴} ∈ V) | |
3 | 2 | adantr 261 | . . . 4 ⊢ ((𝐴 ∈ V ∧ 𝐵 ∈ V) → {𝐴} ∈ V) |
4 | prexgOLD 3946 | . . . 4 ⊢ ((𝐴 ∈ V ∧ 𝐵 ∈ V) → {𝐴, 𝐵} ∈ V) | |
5 | 3, 4 | jca 290 | . . 3 ⊢ ((𝐴 ∈ V ∧ 𝐵 ∈ V) → ({𝐴} ∈ V ∧ {𝐴, 𝐵} ∈ V)) |
6 | prexgOLD 3946 | . . 3 ⊢ (({𝐴} ∈ V ∧ {𝐴, 𝐵} ∈ V) → {{𝐴}, {𝐴, 𝐵}} ∈ V) | |
7 | 5, 6 | syl 14 | . 2 ⊢ ((𝐴 ∈ V ∧ 𝐵 ∈ V) → {{𝐴}, {𝐴, 𝐵}} ∈ V) |
8 | 1, 7 | eqeltrd 2114 | 1 ⊢ ((𝐴 ∈ V ∧ 𝐵 ∈ V) → 〈𝐴, 𝐵〉 ∈ V) |
Colors of variables: wff set class |
Syntax hints: → wi 4 ∧ wa 97 ∈ wcel 1393 Vcvv 2557 {csn 3375 {cpr 3376 〈cop 3378 |
This theorem was proved from axioms: ax-1 5 ax-2 6 ax-mp 7 ax-ia1 99 ax-ia2 100 ax-ia3 101 ax-io 630 ax-5 1336 ax-7 1337 ax-gen 1338 ax-ie1 1382 ax-ie2 1383 ax-8 1395 ax-10 1396 ax-11 1397 ax-i12 1398 ax-bndl 1399 ax-4 1400 ax-14 1405 ax-17 1419 ax-i9 1423 ax-ial 1427 ax-i5r 1428 ax-ext 2022 ax-sep 3875 ax-pow 3927 ax-pr 3944 |
This theorem depends on definitions: df-bi 110 df-3an 887 df-tru 1246 df-nf 1350 df-sb 1646 df-clab 2027 df-cleq 2033 df-clel 2036 df-nfc 2167 df-v 2559 df-un 2922 df-in 2924 df-ss 2931 df-pw 3361 df-sn 3381 df-pr 3382 df-op 3384 |
This theorem is referenced by: otth2 3978 opeliunxp 4395 opbrop 4419 relsnop 4444 op2ndb 4804 opswapg 4807 elxp4 4808 elxp5 4809 fvsn 5358 resfunexg 5382 fliftel 5433 |
Copyright terms: Public domain | W3C validator |