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Mathbox for Alexander van der Vekens |
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Mirrors > Home > MPE Home > Th. List > Mathboxes > funop1 | Structured version Visualization version GIF version |
Description: A function is an ordered pair iff it is a singleton of an ordered pair. (Contributed by AV, 20-Sep-2020.) (Avoid depending on this detail.) |
Ref | Expression |
---|---|
funop1 | ⊢ (∃𝑥∃𝑦 𝐹 = ⟨𝑥, 𝑦⟩ → (Fun 𝐹 ↔ ∃𝑥∃𝑦 𝐹 = {⟨𝑥, 𝑦⟩})) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | opeq12 4876 | . . . 4 ⊢ ((𝑥 = 𝑣 ∧ 𝑦 = 𝑤) → ⟨𝑥, 𝑦⟩ = ⟨𝑣, 𝑤⟩) | |
2 | 1 | eqeq2d 2741 | . . 3 ⊢ ((𝑥 = 𝑣 ∧ 𝑦 = 𝑤) → (𝐹 = ⟨𝑥, 𝑦⟩ ↔ 𝐹 = ⟨𝑣, 𝑤⟩)) |
3 | 2 | cbvex2vw 2042 | . 2 ⊢ (∃𝑥∃𝑦 𝐹 = ⟨𝑥, 𝑦⟩ ↔ ∃𝑣∃𝑤 𝐹 = ⟨𝑣, 𝑤⟩) |
4 | vex 3476 | . . . . . . 7 ⊢ 𝑣 ∈ V | |
5 | vex 3476 | . . . . . . 7 ⊢ 𝑤 ∈ V | |
6 | 4, 5 | funopsn 7149 | . . . . . 6 ⊢ ((Fun 𝐹 ∧ 𝐹 = ⟨𝑣, 𝑤⟩) → ∃𝑎(𝑣 = {𝑎} ∧ 𝐹 = {⟨𝑎, 𝑎⟩})) |
7 | vex 3476 | . . . . . . . . 9 ⊢ 𝑎 ∈ V | |
8 | opeq12 4876 | . . . . . . . . . . 11 ⊢ ((𝑥 = 𝑎 ∧ 𝑦 = 𝑎) → ⟨𝑥, 𝑦⟩ = ⟨𝑎, 𝑎⟩) | |
9 | 8 | sneqd 4641 | . . . . . . . . . 10 ⊢ ((𝑥 = 𝑎 ∧ 𝑦 = 𝑎) → {⟨𝑥, 𝑦⟩} = {⟨𝑎, 𝑎⟩}) |
10 | 9 | eqeq2d 2741 | . . . . . . . . 9 ⊢ ((𝑥 = 𝑎 ∧ 𝑦 = 𝑎) → (𝐹 = {⟨𝑥, 𝑦⟩} ↔ 𝐹 = {⟨𝑎, 𝑎⟩})) |
11 | 7, 7, 10 | spc2ev 3598 | . . . . . . . 8 ⊢ (𝐹 = {⟨𝑎, 𝑎⟩} → ∃𝑥∃𝑦 𝐹 = {⟨𝑥, 𝑦⟩}) |
12 | 11 | adantl 480 | . . . . . . 7 ⊢ ((𝑣 = {𝑎} ∧ 𝐹 = {⟨𝑎, 𝑎⟩}) → ∃𝑥∃𝑦 𝐹 = {⟨𝑥, 𝑦⟩}) |
13 | 12 | exlimiv 1931 | . . . . . 6 ⊢ (∃𝑎(𝑣 = {𝑎} ∧ 𝐹 = {⟨𝑎, 𝑎⟩}) → ∃𝑥∃𝑦 𝐹 = {⟨𝑥, 𝑦⟩}) |
14 | 6, 13 | syl 17 | . . . . 5 ⊢ ((Fun 𝐹 ∧ 𝐹 = ⟨𝑣, 𝑤⟩) → ∃𝑥∃𝑦 𝐹 = {⟨𝑥, 𝑦⟩}) |
15 | 14 | expcom 412 | . . . 4 ⊢ (𝐹 = ⟨𝑣, 𝑤⟩ → (Fun 𝐹 → ∃𝑥∃𝑦 𝐹 = {⟨𝑥, 𝑦⟩})) |
16 | vex 3476 | . . . . . . 7 ⊢ 𝑥 ∈ V | |
17 | vex 3476 | . . . . . . 7 ⊢ 𝑦 ∈ V | |
18 | 16, 17 | funsn 6602 | . . . . . 6 ⊢ Fun {⟨𝑥, 𝑦⟩} |
19 | funeq 6569 | . . . . . 6 ⊢ (𝐹 = {⟨𝑥, 𝑦⟩} → (Fun 𝐹 ↔ Fun {⟨𝑥, 𝑦⟩})) | |
20 | 18, 19 | mpbiri 257 | . . . . 5 ⊢ (𝐹 = {⟨𝑥, 𝑦⟩} → Fun 𝐹) |
21 | 20 | exlimivv 1933 | . . . 4 ⊢ (∃𝑥∃𝑦 𝐹 = {⟨𝑥, 𝑦⟩} → Fun 𝐹) |
22 | 15, 21 | impbid1 224 | . . 3 ⊢ (𝐹 = ⟨𝑣, 𝑤⟩ → (Fun 𝐹 ↔ ∃𝑥∃𝑦 𝐹 = {⟨𝑥, 𝑦⟩})) |
23 | 22 | exlimivv 1933 | . 2 ⊢ (∃𝑣∃𝑤 𝐹 = ⟨𝑣, 𝑤⟩ → (Fun 𝐹 ↔ ∃𝑥∃𝑦 𝐹 = {⟨𝑥, 𝑦⟩})) |
24 | 3, 23 | sylbi 216 | 1 ⊢ (∃𝑥∃𝑦 𝐹 = ⟨𝑥, 𝑦⟩ → (Fun 𝐹 ↔ ∃𝑥∃𝑦 𝐹 = {⟨𝑥, 𝑦⟩})) |
Colors of variables: wff setvar class |
Syntax hints: → wi 4 ↔ wb 205 ∧ wa 394 = wceq 1539 ∃wex 1779 {csn 4629 ⟨cop 4635 Fun wfun 6538 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1795 ax-4 1809 ax-5 1911 ax-6 1969 ax-7 2009 ax-8 2106 ax-9 2114 ax-10 2135 ax-11 2152 ax-12 2169 ax-ext 2701 ax-sep 5300 ax-nul 5307 ax-pr 5428 |
This theorem depends on definitions: df-bi 206 df-an 395 df-or 844 df-3an 1087 df-tru 1542 df-fal 1552 df-ex 1780 df-nf 1784 df-sb 2066 df-mo 2532 df-eu 2561 df-clab 2708 df-cleq 2722 df-clel 2808 df-nfc 2883 df-ne 2939 df-ral 3060 df-rex 3069 df-reu 3375 df-rab 3431 df-v 3474 df-sbc 3779 df-csb 3895 df-dif 3952 df-un 3954 df-in 3956 df-ss 3966 df-nul 4324 df-if 4530 df-sn 4630 df-pr 4632 df-op 4636 df-uni 4910 df-iun 5000 df-br 5150 df-opab 5212 df-mpt 5233 df-id 5575 df-xp 5683 df-rel 5684 df-cnv 5685 df-co 5686 df-dm 5687 df-rn 5688 df-iota 6496 df-fun 6546 df-fn 6547 df-f 6548 df-f1 6549 df-fo 6550 df-f1o 6551 df-fv 6552 |
This theorem is referenced by: (None) |
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