Metamath Proof Explorer |
< Previous
Next >
Nearby theorems |
||
Mirrors > Home > MPE Home > Th. List > abn0 | Structured version Visualization version GIF version |
Description: Nonempty class abstraction. See also ab0 4333. (Contributed by NM, 26-Dec-1996.) (Proof shortened by Mario Carneiro, 11-Nov-2016.) |
Ref | Expression |
---|---|
abn0 | ⊢ ({𝑥 ∣ 𝜑} ≠ ∅ ↔ ∃𝑥𝜑) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | nfab1 2979 | . . 3 ⊢ Ⅎ𝑥{𝑥 ∣ 𝜑} | |
2 | 1 | n0f 4307 | . 2 ⊢ ({𝑥 ∣ 𝜑} ≠ ∅ ↔ ∃𝑥 𝑥 ∈ {𝑥 ∣ 𝜑}) |
3 | abid 2803 | . . 3 ⊢ (𝑥 ∈ {𝑥 ∣ 𝜑} ↔ 𝜑) | |
4 | 3 | exbii 1848 | . 2 ⊢ (∃𝑥 𝑥 ∈ {𝑥 ∣ 𝜑} ↔ ∃𝑥𝜑) |
5 | 2, 4 | bitri 277 | 1 ⊢ ({𝑥 ∣ 𝜑} ≠ ∅ ↔ ∃𝑥𝜑) |
Colors of variables: wff setvar class |
Syntax hints: ↔ wb 208 ∃wex 1780 ∈ wcel 2114 {cab 2799 ≠ wne 3016 ∅c0 4291 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1796 ax-4 1810 ax-5 1911 ax-6 1970 ax-7 2015 ax-8 2116 ax-9 2124 ax-10 2145 ax-11 2161 ax-12 2177 ax-ext 2793 |
This theorem depends on definitions: df-bi 209 df-an 399 df-or 844 df-tru 1540 df-ex 1781 df-nf 1785 df-sb 2070 df-clab 2800 df-cleq 2814 df-clel 2893 df-nfc 2963 df-ne 3017 df-dif 3939 df-nul 4292 |
This theorem is referenced by: intexab 5242 iinexg 5244 relimasn 5952 inisegn0 5961 mapprc 8410 modom 8719 tz9.1c 9172 scott0 9315 scott0s 9317 cp 9320 karden 9324 acnrcl 9468 aceq3lem 9546 cff 9670 cff1 9680 cfss 9687 domtriomlem 9864 axdclem 9941 nqpr 10436 supadd 11609 supmul 11613 hashf1lem2 13815 hashf1 13816 mreiincl 16867 efgval 18843 efger 18844 birthdaylem3 25531 disjex 30342 disjexc 30343 mppsval 32819 mblfinlem3 34946 ismblfin 34948 itg2addnc 34961 sdclem1 35033 upbdrech 41592 |
Copyright terms: Public domain | W3C validator |