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| Mirrors > Home > MPE Home > Th. List > predprc | Structured version Visualization version GIF version | ||
| Description: The predecessor of a proper class is empty. (Contributed by Scott Fenton, 25-Nov-2024.) |
| Ref | Expression |
|---|---|
| predprc | ⊢ (¬ 𝑋 ∈ V → Pred(𝑅, 𝐴, 𝑋) = ∅) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | df-pred 6255 | . 2 ⊢ Pred(𝑅, 𝐴, 𝑋) = (𝐴 ∩ (◡𝑅 “ {𝑋})) | |
| 2 | snprc 4671 | . . . . . . 7 ⊢ (¬ 𝑋 ∈ V ↔ {𝑋} = ∅) | |
| 3 | 2 | biimpi 216 | . . . . . 6 ⊢ (¬ 𝑋 ∈ V → {𝑋} = ∅) |
| 4 | 3 | imaeq2d 6015 | . . . . 5 ⊢ (¬ 𝑋 ∈ V → (◡𝑅 “ {𝑋}) = (◡𝑅 “ ∅)) |
| 5 | ima0 6032 | . . . . 5 ⊢ (◡𝑅 “ ∅) = ∅ | |
| 6 | 4, 5 | eqtrdi 2784 | . . . 4 ⊢ (¬ 𝑋 ∈ V → (◡𝑅 “ {𝑋}) = ∅) |
| 7 | 6 | ineq2d 4169 | . . 3 ⊢ (¬ 𝑋 ∈ V → (𝐴 ∩ (◡𝑅 “ {𝑋})) = (𝐴 ∩ ∅)) |
| 8 | in0 4344 | . . 3 ⊢ (𝐴 ∩ ∅) = ∅ | |
| 9 | 7, 8 | eqtrdi 2784 | . 2 ⊢ (¬ 𝑋 ∈ V → (𝐴 ∩ (◡𝑅 “ {𝑋})) = ∅) |
| 10 | 1, 9 | eqtrid 2780 | 1 ⊢ (¬ 𝑋 ∈ V → Pred(𝑅, 𝐴, 𝑋) = ∅) |
| Colors of variables: wff setvar class |
| Syntax hints: ¬ wn 3 → wi 4 = wceq 1541 ∈ wcel 2113 Vcvv 3437 ∩ cin 3897 ∅c0 4282 {csn 4577 ◡ccnv 5620 “ cima 5624 Predcpred 6254 |
| 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 1968 ax-7 2009 ax-8 2115 ax-9 2123 ax-ext 2705 ax-sep 5238 ax-nul 5248 ax-pr 5374 |
| This theorem depends on definitions: df-bi 207 df-an 396 df-or 848 df-3an 1088 df-tru 1544 df-fal 1554 df-ex 1781 df-sb 2068 df-clab 2712 df-cleq 2725 df-clel 2808 df-rab 3397 df-v 3439 df-dif 3901 df-un 3903 df-in 3905 df-ss 3915 df-nul 4283 df-if 4477 df-sn 4578 df-pr 4580 df-op 4584 df-br 5096 df-opab 5158 df-xp 5627 df-cnv 5629 df-dm 5631 df-rn 5632 df-res 5633 df-ima 5634 df-pred 6255 |
| This theorem is referenced by: predres 6293 |
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