![]() |
Metamath Proof Explorer |
< Previous
Next >
Nearby theorems |
|
Mirrors > Home > MPE Home > Th. List > 1stval2 | Structured version Visualization version GIF version |
Description: Alternate value of the function that extracts the first member of an ordered pair. Definition 5.13 (i) of [Monk1] p. 52. (Contributed by NM, 18-Aug-2006.) |
Ref | Expression |
---|---|
1stval2 | ⊢ (𝐴 ∈ (V × V) → (1st ‘𝐴) = ∩ ∩ 𝐴) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | elvv 5763 | . 2 ⊢ (𝐴 ∈ (V × V) ↔ ∃𝑥∃𝑦 𝐴 = 〈𝑥, 𝑦〉) | |
2 | vex 3482 | . . . . . 6 ⊢ 𝑥 ∈ V | |
3 | vex 3482 | . . . . . 6 ⊢ 𝑦 ∈ V | |
4 | 2, 3 | op1st 8021 | . . . . 5 ⊢ (1st ‘〈𝑥, 𝑦〉) = 𝑥 |
5 | 2, 3 | op1stb 5482 | . . . . 5 ⊢ ∩ ∩ 〈𝑥, 𝑦〉 = 𝑥 |
6 | 4, 5 | eqtr4i 2766 | . . . 4 ⊢ (1st ‘〈𝑥, 𝑦〉) = ∩ ∩ 〈𝑥, 𝑦〉 |
7 | fveq2 6907 | . . . 4 ⊢ (𝐴 = 〈𝑥, 𝑦〉 → (1st ‘𝐴) = (1st ‘〈𝑥, 𝑦〉)) | |
8 | inteq 4954 | . . . . 5 ⊢ (𝐴 = 〈𝑥, 𝑦〉 → ∩ 𝐴 = ∩ 〈𝑥, 𝑦〉) | |
9 | 8 | inteqd 4956 | . . . 4 ⊢ (𝐴 = 〈𝑥, 𝑦〉 → ∩ ∩ 𝐴 = ∩ ∩ 〈𝑥, 𝑦〉) |
10 | 6, 7, 9 | 3eqtr4a 2801 | . . 3 ⊢ (𝐴 = 〈𝑥, 𝑦〉 → (1st ‘𝐴) = ∩ ∩ 𝐴) |
11 | 10 | exlimivv 1930 | . 2 ⊢ (∃𝑥∃𝑦 𝐴 = 〈𝑥, 𝑦〉 → (1st ‘𝐴) = ∩ ∩ 𝐴) |
12 | 1, 11 | sylbi 217 | 1 ⊢ (𝐴 ∈ (V × V) → (1st ‘𝐴) = ∩ ∩ 𝐴) |
Colors of variables: wff setvar class |
Syntax hints: → wi 4 = wceq 1537 ∃wex 1776 ∈ wcel 2106 Vcvv 3478 〈cop 4637 ∩ cint 4951 × cxp 5687 ‘cfv 6563 1st c1st 8011 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1792 ax-4 1806 ax-5 1908 ax-6 1965 ax-7 2005 ax-8 2108 ax-9 2116 ax-10 2139 ax-11 2155 ax-12 2175 ax-ext 2706 ax-sep 5302 ax-nul 5312 ax-pr 5438 ax-un 7754 |
This theorem depends on definitions: df-bi 207 df-an 396 df-or 848 df-3an 1088 df-tru 1540 df-fal 1550 df-ex 1777 df-nf 1781 df-sb 2063 df-mo 2538 df-eu 2567 df-clab 2713 df-cleq 2727 df-clel 2814 df-nfc 2890 df-ral 3060 df-rex 3069 df-rab 3434 df-v 3480 df-dif 3966 df-un 3968 df-in 3970 df-ss 3980 df-nul 4340 df-if 4532 df-sn 4632 df-pr 4634 df-op 4638 df-uni 4913 df-int 4952 df-br 5149 df-opab 5211 df-mpt 5232 df-id 5583 df-xp 5695 df-rel 5696 df-cnv 5697 df-co 5698 df-dm 5699 df-rn 5700 df-iota 6516 df-fun 6565 df-fv 6571 df-1st 8013 |
This theorem is referenced by: 1stdm 8064 |
Copyright terms: Public domain | W3C validator |