![]() |
Metamath Proof Explorer |
< Previous
Next >
Nearby theorems |
|
Mirrors > Home > MPE Home > Th. List > rexeq | Structured version Visualization version GIF version |
Description: Equality theorem for restricted existential quantifier. (Contributed by NM, 29-Oct-1995.) Remove usage of ax-10 2138, ax-11 2155, and ax-12 2172. (Revised by Steven Nguyen, 30-Apr-2023.) Shorten other proofs. (Revised by Wolf Lammen, 8-Mar-2025.) |
Ref | Expression |
---|---|
rexeq | ⊢ (𝐴 = 𝐵 → (∃𝑥 ∈ 𝐴 𝜑 ↔ ∃𝑥 ∈ 𝐵 𝜑)) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | dfcleq 2726 | . . 3 ⊢ (𝐴 = 𝐵 ↔ ∀𝑥(𝑥 ∈ 𝐴 ↔ 𝑥 ∈ 𝐵)) | |
2 | anbi1 633 | . . . 4 ⊢ ((𝑥 ∈ 𝐴 ↔ 𝑥 ∈ 𝐵) → ((𝑥 ∈ 𝐴 ∧ 𝜑) ↔ (𝑥 ∈ 𝐵 ∧ 𝜑))) | |
3 | 2 | alexbii 1836 | . . 3 ⊢ (∀𝑥(𝑥 ∈ 𝐴 ↔ 𝑥 ∈ 𝐵) → (∃𝑥(𝑥 ∈ 𝐴 ∧ 𝜑) ↔ ∃𝑥(𝑥 ∈ 𝐵 ∧ 𝜑))) |
4 | 1, 3 | sylbi 216 | . 2 ⊢ (𝐴 = 𝐵 → (∃𝑥(𝑥 ∈ 𝐴 ∧ 𝜑) ↔ ∃𝑥(𝑥 ∈ 𝐵 ∧ 𝜑))) |
5 | df-rex 3072 | . 2 ⊢ (∃𝑥 ∈ 𝐴 𝜑 ↔ ∃𝑥(𝑥 ∈ 𝐴 ∧ 𝜑)) | |
6 | df-rex 3072 | . 2 ⊢ (∃𝑥 ∈ 𝐵 𝜑 ↔ ∃𝑥(𝑥 ∈ 𝐵 ∧ 𝜑)) | |
7 | 4, 5, 6 | 3bitr4g 314 | 1 ⊢ (𝐴 = 𝐵 → (∃𝑥 ∈ 𝐴 𝜑 ↔ ∃𝑥 ∈ 𝐵 𝜑)) |
Colors of variables: wff setvar class |
Syntax hints: → wi 4 ↔ wb 205 ∧ wa 397 ∀wal 1540 = wceq 1542 ∃wex 1782 ∈ wcel 2107 ∃wrex 3071 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1798 ax-4 1812 ax-5 1914 ax-6 1972 ax-7 2012 ax-9 2117 ax-ext 2704 |
This theorem depends on definitions: df-bi 206 df-an 398 df-ex 1783 df-cleq 2725 df-rex 3072 |
This theorem is referenced by: raleq 3323 rexeqi 3325 rexeqdv 3327 reueq1 3416 unieqOLD 4921 axrep6g 5294 exss 5464 qseq1 8757 pssnn 9168 1sdomOLD 9249 pssnnOLD 9265 indexfi 9360 supeq1 9440 bnd2 9888 dfac2b 10125 cflem 10241 cflecard 10248 cfeq0 10251 cfsuc 10252 cfflb 10254 cofsmo 10264 elwina 10681 eltskg 10745 rankcf 10772 elnp 10982 elnpi 10983 genpv 10994 xrsupsslem 13286 xrinfmsslem 13287 xrsupss 13288 xrinfmss 13289 hashge2el2difr 14442 cat1 18047 isdrs 18254 isipodrs 18490 neifval 22603 ishaus 22826 2ndc1stc 22955 1stcrest 22957 lly1stc 23000 isref 23013 islocfin 23021 tx1stc 23154 isust 23708 iscfilu 23793 met1stc 24030 iscfil 24782 noetasuplem4 27239 precsexlemcbv 27652 precsexlem3 27655 ishpg 28010 isgrpo 29750 chne0 30747 pstmfval 32876 dya2iocuni 33282 satfvsuc 34352 satf0suc 34367 sat1el2xp 34370 fmlasuc0 34375 altxpeq1 34945 altxpeq2 34946 elhf2 35147 bj-sngleq 35848 cover2g 36584 indexdom 36602 istotbnd 36637 pmapglb2xN 38643 paddval 38669 elpadd0 38680 diophrex 41513 hbtlem1 41865 hbtlem7 41867 tfsconcatb0 42094 mnuop23d 43025 ismnushort 43060 sprval 46147 sprsymrelfvlem 46158 sprsymrelfv 46162 sprsymrelfo 46165 prprval 46182 |
Copyright terms: Public domain | W3C validator |