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Mirrors > Home > MPE Home > Th. List > alnex | Structured version Visualization version GIF version |
Description: Theorem 19.7 of [Margaris] p. 89. (Contributed by NM, 12-Mar-1993.) |
Ref | Expression |
---|---|
alnex | ⊢ (∀𝑥 ¬ 𝜑 ↔ ¬ ∃𝑥𝜑) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | df-ex 1696 | . 2 ⊢ (∃𝑥𝜑 ↔ ¬ ∀𝑥 ¬ 𝜑) | |
2 | 1 | con2bii 346 | 1 ⊢ (∀𝑥 ¬ 𝜑 ↔ ¬ ∃𝑥𝜑) |
Colors of variables: wff setvar class |
Syntax hints: ¬ wn 3 ↔ wb 195 ∀wal 1473 ∃wex 1695 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 |
This theorem depends on definitions: df-bi 196 df-ex 1696 |
This theorem is referenced by: nf3 1703 nex 1722 alex 1743 2exnaln 1746 aleximi 1749 19.38 1757 alinexa 1759 alexn 1760 nexdh 1779 19.43 1799 19.43OLD 1800 19.33b 1802 nexdvOLD 1852 cbvexdva 2271 mo2v 2465 ralnex 2975 mo2icl 3352 disjsn 4192 dm0rn0 5263 reldm0 5264 iotanul 5783 imadif 5887 dffv2 6181 kmlem4 8858 axpowndlem3 9300 axpownd 9302 hashgt0elex 13050 nmo 28709 bnj1143 30115 unbdqndv1 31669 bj-nf3 31767 bj-nexdh 31790 bj-modal5e 31825 axc11n11r 31860 bj-hbntbi 31882 bj-modal4e 31892 wl-nfeqfb 32502 wl-sb8et 32513 wl-lem-nexmo 32528 n0el 33164 pm10.251 37581 pm10.57 37592 elnev 37661 falseral0 40308 zrninitoringc 41863 alimp-no-surprise 42336 |
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