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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 6252 | . 2 ⊢ Pred(𝑅, 𝐴, 𝑋) = (𝐴 ∩ (◡𝑅 “ {𝑋})) | |
| 2 | snprc 4649 | . . . . . . 7 ⊢ (¬ 𝑋 ∈ V ↔ {𝑋} = ∅) | |
| 3 | 2 | biimpi 217 | . . . . . 6 ⊢ (¬ 𝑋 ∈ V → {𝑋} = ∅) |
| 4 | 3 | imaeq2d 6012 | . . . . 5 ⊢ (¬ 𝑋 ∈ V → (◡𝑅 “ {𝑋}) = (◡𝑅 “ ∅)) |
| 5 | ima0 6029 | . . . . 5 ⊢ (◡𝑅 “ ∅) = ∅ | |
| 6 | 4, 5 | eqtrdi 2790 | . . . 4 ⊢ (¬ 𝑋 ∈ V → (◡𝑅 “ {𝑋}) = ∅) |
| 7 | 6 | ineq2d 4149 | . . 3 ⊢ (¬ 𝑋 ∈ V → (𝐴 ∩ (◡𝑅 “ {𝑋})) = (𝐴 ∩ ∅)) |
| 8 | in0 4323 | . . 3 ⊢ (𝐴 ∩ ∅) = ∅ | |
| 9 | 7, 8 | eqtrdi 2790 | . 2 ⊢ (¬ 𝑋 ∈ V → (𝐴 ∩ (◡𝑅 “ {𝑋})) = ∅) |
| 10 | 1, 9 | eqtrid 2786 | 1 ⊢ (¬ 𝑋 ∈ V → Pred(𝑅, 𝐴, 𝑋) = ∅) |
| Colors of variables: wff setvar class |
| Syntax hints: ¬ wn 3 → wi 4 = wceq 1547 ∈ wcel 2119 Vcvv 3431 ∩ cin 3882 ∅c0 4261 {csn 4555 ◡ccnv 5617 “ cima 5621 Predcpred 6251 |
| This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1802 ax-4 1816 ax-5 1917 ax-6 1974 ax-7 2015 ax-8 2121 ax-9 2129 ax-ext 2711 ax-sep 5218 ax-pr 5362 |
| This theorem depends on definitions: df-bi 208 df-an 397 df-or 854 df-3an 1094 df-tru 1550 df-fal 1560 df-ex 1787 df-sb 2074 df-clab 2718 df-cleq 2731 df-clel 2814 df-rab 3392 df-v 3433 df-dif 3886 df-un 3888 df-in 3890 df-ss 3900 df-nul 4262 df-if 4455 df-sn 4556 df-pr 4558 df-op 4562 df-br 5073 df-opab 5135 df-xp 5624 df-cnv 5626 df-dm 5628 df-rn 5629 df-res 5630 df-ima 5631 df-pred 6252 |
| This theorem is referenced by: predres 6290 |
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