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| Mirrors > Home > ILE Home > Th. List > nfre1 | GIF version | ||
| Description: 𝑥 is not free in ∃𝑥 ∈ 𝐴𝜑. (Contributed by NM, 19-Mar-1997.) (Revised by Mario Carneiro, 7-Oct-2016.) |
| Ref | Expression |
|---|---|
| nfre1 | ⊢ Ⅎ𝑥∃𝑥 ∈ 𝐴 𝜑 |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | df-rex 2489 | . 2 ⊢ (∃𝑥 ∈ 𝐴 𝜑 ↔ ∃𝑥(𝑥 ∈ 𝐴 ∧ 𝜑)) | |
| 2 | nfe1 1518 | . 2 ⊢ Ⅎ𝑥∃𝑥(𝑥 ∈ 𝐴 ∧ 𝜑) | |
| 3 | 1, 2 | nfxfr 1496 | 1 ⊢ Ⅎ𝑥∃𝑥 ∈ 𝐴 𝜑 |
| Colors of variables: wff set class |
| Syntax hints: ∧ wa 104 Ⅎwnf 1482 ∃wex 1514 ∈ wcel 2175 ∃wrex 2484 |
| This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-ia1 106 ax-ia2 107 ax-ia3 108 ax-5 1469 ax-gen 1471 ax-ie1 1515 |
| This theorem depends on definitions: df-bi 117 df-nf 1483 df-rex 2489 |
| This theorem is referenced by: r19.29an 2647 nfiu1 3956 fun11iun 5542 eusvobj2 5929 fodjuomnilemdc 7245 ismkvnex 7256 prarloclem3step 7608 prmuloc2 7679 ltexprlemm 7712 caucvgprprlemaddq 7820 caucvgsrlemgt1 7907 axpre-suploclemres 8013 supinfneg 9715 infsupneg 9716 lbzbi 9736 divalglemeunn 12174 divalglemeuneg 12176 bezoutlemmain 12261 bezout 12274 lss1d 14087 pw1nct 15873 isomninnlem 15902 trirec0 15916 ismkvnnlem 15924 |
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