|   | Mathbox for Richard Penner | < Previous  
      Next > Nearby theorems | |
| Mirrors > Home > MPE Home > Th. List > Mathboxes > elcnvlem | Structured version Visualization version GIF version | ||
| Description: Two ways to say a set is a member of the converse of a class. (Contributed by RP, 19-Aug-2020.) | 
| Ref | Expression | 
|---|---|
| elcnvlem.f | ⊢ 𝐹 = (𝑥 ∈ (V × V) ↦ 〈(2nd ‘𝑥), (1st ‘𝑥)〉) | 
| Ref | Expression | 
|---|---|
| elcnvlem | ⊢ (𝐴 ∈ ◡𝐵 ↔ (𝐴 ∈ (V × V) ∧ (𝐹‘𝐴) ∈ 𝐵)) | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | elcnv2 5888 | . 2 ⊢ (𝐴 ∈ ◡𝐵 ↔ ∃𝑢∃𝑣(𝐴 = 〈𝑢, 𝑣〉 ∧ 〈𝑣, 𝑢〉 ∈ 𝐵)) | |
| 2 | fveq2 6906 | . . . . 5 ⊢ (𝐴 = 〈𝑢, 𝑣〉 → (𝐹‘𝐴) = (𝐹‘〈𝑢, 𝑣〉)) | |
| 3 | vex 3484 | . . . . . . 7 ⊢ 𝑢 ∈ V | |
| 4 | vex 3484 | . . . . . . 7 ⊢ 𝑣 ∈ V | |
| 5 | 3, 4 | opelvv 5725 | . . . . . 6 ⊢ 〈𝑢, 𝑣〉 ∈ (V × V) | 
| 6 | 3, 4 | op2ndd 8025 | . . . . . . . 8 ⊢ (𝑥 = 〈𝑢, 𝑣〉 → (2nd ‘𝑥) = 𝑣) | 
| 7 | 3, 4 | op1std 8024 | . . . . . . . 8 ⊢ (𝑥 = 〈𝑢, 𝑣〉 → (1st ‘𝑥) = 𝑢) | 
| 8 | 6, 7 | opeq12d 4881 | . . . . . . 7 ⊢ (𝑥 = 〈𝑢, 𝑣〉 → 〈(2nd ‘𝑥), (1st ‘𝑥)〉 = 〈𝑣, 𝑢〉) | 
| 9 | elcnvlem.f | . . . . . . 7 ⊢ 𝐹 = (𝑥 ∈ (V × V) ↦ 〈(2nd ‘𝑥), (1st ‘𝑥)〉) | |
| 10 | opex 5469 | . . . . . . 7 ⊢ 〈𝑣, 𝑢〉 ∈ V | |
| 11 | 8, 9, 10 | fvmpt 7016 | . . . . . 6 ⊢ (〈𝑢, 𝑣〉 ∈ (V × V) → (𝐹‘〈𝑢, 𝑣〉) = 〈𝑣, 𝑢〉) | 
| 12 | 5, 11 | ax-mp 5 | . . . . 5 ⊢ (𝐹‘〈𝑢, 𝑣〉) = 〈𝑣, 𝑢〉 | 
| 13 | 2, 12 | eqtrdi 2793 | . . . 4 ⊢ (𝐴 = 〈𝑢, 𝑣〉 → (𝐹‘𝐴) = 〈𝑣, 𝑢〉) | 
| 14 | 13 | eleq1d 2826 | . . 3 ⊢ (𝐴 = 〈𝑢, 𝑣〉 → ((𝐹‘𝐴) ∈ 𝐵 ↔ 〈𝑣, 𝑢〉 ∈ 𝐵)) | 
| 15 | 14 | copsex2gb 5816 | . 2 ⊢ (∃𝑢∃𝑣(𝐴 = 〈𝑢, 𝑣〉 ∧ 〈𝑣, 𝑢〉 ∈ 𝐵) ↔ (𝐴 ∈ (V × V) ∧ (𝐹‘𝐴) ∈ 𝐵)) | 
| 16 | 1, 15 | bitri 275 | 1 ⊢ (𝐴 ∈ ◡𝐵 ↔ (𝐴 ∈ (V × V) ∧ (𝐹‘𝐴) ∈ 𝐵)) | 
| Colors of variables: wff setvar class | 
| Syntax hints: ↔ wb 206 ∧ wa 395 = wceq 1540 ∃wex 1779 ∈ wcel 2108 Vcvv 3480 〈cop 4632 ↦ cmpt 5225 × cxp 5683 ◡ccnv 5684 ‘cfv 6561 1st c1st 8012 2nd c2nd 8013 | 
| 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 1910 ax-6 1967 ax-7 2007 ax-8 2110 ax-9 2118 ax-10 2141 ax-11 2157 ax-12 2177 ax-ext 2708 ax-sep 5296 ax-nul 5306 ax-pr 5432 ax-un 7755 | 
| This theorem depends on definitions: df-bi 207 df-an 396 df-or 849 df-3an 1089 df-tru 1543 df-fal 1553 df-ex 1780 df-nf 1784 df-sb 2065 df-mo 2540 df-eu 2569 df-clab 2715 df-cleq 2729 df-clel 2816 df-nfc 2892 df-ral 3062 df-rex 3071 df-rab 3437 df-v 3482 df-dif 3954 df-un 3956 df-in 3958 df-ss 3968 df-nul 4334 df-if 4526 df-sn 4627 df-pr 4629 df-op 4633 df-uni 4908 df-br 5144 df-opab 5206 df-mpt 5226 df-id 5578 df-xp 5691 df-rel 5692 df-cnv 5693 df-co 5694 df-dm 5695 df-rn 5696 df-iota 6514 df-fun 6563 df-fv 6569 df-1st 8014 df-2nd 8015 | 
| This theorem is referenced by: elcnvintab 43615 | 
| Copyright terms: Public domain | W3C validator |