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Related theorems GIF version |
| Description: Define negated membership. |
| Ref | Expression |
|---|---|
| df-nel | ⊢ (A ∉ B ↔ ¬ A ∈ B) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | cA | . . 3 class A | |
| 2 | cB | . . 3 class B | |
| 3 | 1, 2 | wnel 1629 | . 2 wff A ∉ B |
| 4 | 1, 2 | wcel 994 | . . 3 wff A ∈ B |
| 5 | 4 | wn 2 | . 2 wff ¬ A ∈ B |
| 6 | 3, 5 | wb 144 | 1 wff (A ∉ B ↔ ¬ A ∈ B) |
| Colors of variables: wff set class |
| This definition is referenced by: neleq1 1688 neleq2 1689 ru 1984 snnex 3100 fiprc 4574 ruv 4744 ruALT 4745 pnfnre 5650 mnfnre 5651 ltxrlt 5654 renepnf 5691 renemnf 5692 xrltnr 5695 pnfnlt 5700 nltmnf 5701 sqr2irr 6930 nthruc 6946 eirr 7599 egt2OLD 7600 elt3OLD 7601 egt2lt3 7602 lpni 11417 compfipin0 11493 fbasfip 11627 filfbas 11628 opnfbas 11629 fbunfip 11631 fgfil 11638 extbas1 11641 filrn 11643 rnelfmlem 11698 fcluscomp 11733 tailfb 11762 |