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Mirrors > Home > ILE Home > Th. List > op1stg | GIF version |
Description: Extract the first member of an ordered pair. (Contributed by NM, 19-Jul-2005.) |
Ref | Expression |
---|---|
op1stg | ⊢ ((𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊) → (1st ‘〈𝐴, 𝐵〉) = 𝐴) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | opeq1 3752 | . . . 4 ⊢ (𝑥 = 𝐴 → 〈𝑥, 𝑦〉 = 〈𝐴, 𝑦〉) | |
2 | 1 | fveq2d 5484 | . . 3 ⊢ (𝑥 = 𝐴 → (1st ‘〈𝑥, 𝑦〉) = (1st ‘〈𝐴, 𝑦〉)) |
3 | id 19 | . . 3 ⊢ (𝑥 = 𝐴 → 𝑥 = 𝐴) | |
4 | 2, 3 | eqeq12d 2179 | . 2 ⊢ (𝑥 = 𝐴 → ((1st ‘〈𝑥, 𝑦〉) = 𝑥 ↔ (1st ‘〈𝐴, 𝑦〉) = 𝐴)) |
5 | opeq2 3753 | . . . 4 ⊢ (𝑦 = 𝐵 → 〈𝐴, 𝑦〉 = 〈𝐴, 𝐵〉) | |
6 | 5 | fveq2d 5484 | . . 3 ⊢ (𝑦 = 𝐵 → (1st ‘〈𝐴, 𝑦〉) = (1st ‘〈𝐴, 𝐵〉)) |
7 | 6 | eqeq1d 2173 | . 2 ⊢ (𝑦 = 𝐵 → ((1st ‘〈𝐴, 𝑦〉) = 𝐴 ↔ (1st ‘〈𝐴, 𝐵〉) = 𝐴)) |
8 | vex 2724 | . . 3 ⊢ 𝑥 ∈ V | |
9 | vex 2724 | . . 3 ⊢ 𝑦 ∈ V | |
10 | 8, 9 | op1st 6106 | . 2 ⊢ (1st ‘〈𝑥, 𝑦〉) = 𝑥 |
11 | 4, 7, 10 | vtocl2g 2785 | 1 ⊢ ((𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊) → (1st ‘〈𝐴, 𝐵〉) = 𝐴) |
Colors of variables: wff set class |
Syntax hints: → wi 4 ∧ wa 103 = wceq 1342 ∈ wcel 2135 〈cop 3573 ‘cfv 5182 1st c1st 6098 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-ia1 105 ax-ia2 106 ax-ia3 107 ax-io 699 ax-5 1434 ax-7 1435 ax-gen 1436 ax-ie1 1480 ax-ie2 1481 ax-8 1491 ax-10 1492 ax-11 1493 ax-i12 1494 ax-bndl 1496 ax-4 1497 ax-17 1513 ax-i9 1517 ax-ial 1521 ax-i5r 1522 ax-13 2137 ax-14 2138 ax-ext 2146 ax-sep 4094 ax-pow 4147 ax-pr 4181 ax-un 4405 |
This theorem depends on definitions: df-bi 116 df-3an 969 df-tru 1345 df-nf 1448 df-sb 1750 df-eu 2016 df-mo 2017 df-clab 2151 df-cleq 2157 df-clel 2160 df-nfc 2295 df-ral 2447 df-rex 2448 df-v 2723 df-sbc 2947 df-un 3115 df-in 3117 df-ss 3124 df-pw 3555 df-sn 3576 df-pr 3577 df-op 3579 df-uni 3784 df-br 3977 df-opab 4038 df-mpt 4039 df-id 4265 df-xp 4604 df-rel 4605 df-cnv 4606 df-co 4607 df-dm 4608 df-rn 4609 df-iota 5147 df-fun 5184 df-fv 5190 df-1st 6100 |
This theorem is referenced by: ot1stg 6112 ot2ndg 6113 1stconst 6180 algrflemg 6189 mpoxopn0yelv 6198 mpoxopoveq 6199 xpmapenlem 6806 1stinl 7030 1stinr 7032 mulpipq 7304 suplocexprlemlub 7656 aprcl 8535 frecuzrdgg 10341 qredeu 12008 qnumdenbi 12101 upxp 12813 uptx 12815 txmetcnp 13059 |
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