| Metamath Proof Explorer |
< Previous
Next >
Nearby theorems |
||
| 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 6299 | . 2 ⊢ Pred(𝑅, 𝐴, 𝑋) = (𝐴 ∩ (◡𝑅 “ {𝑋})) | |
| 2 | snprc 4678 | . . . . . . 7 ⊢ (¬ 𝑋 ∈ V ↔ {𝑋} = ∅) | |
| 3 | 2 | biimpi 219 | . . . . . 6 ⊢ (¬ 𝑋 ∈ V → {𝑋} = ∅) |
| 4 | 3 | imaeq2d 6056 | . . . . 5 ⊢ (¬ 𝑋 ∈ V → (◡𝑅 “ {𝑋}) = (◡𝑅 “ ∅)) |
| 5 | ima0 6073 | . . . . 5 ⊢ (◡𝑅 “ ∅) = ∅ | |
| 6 | 4, 5 | eqtrdi 2811 | . . . 4 ⊢ (¬ 𝑋 ∈ V → (◡𝑅 “ {𝑋}) = ∅) |
| 7 | 6 | ineq2d 4166 | . . 3 ⊢ (¬ 𝑋 ∈ V → (𝐴 ∩ (◡𝑅 “ {𝑋})) = (𝐴 ∩ ∅)) |
| 8 | in0 4345 | . . 3 ⊢ (𝐴 ∩ ∅) = ∅ | |
| 9 | 7, 8 | eqtrdi 2811 | . 2 ⊢ (¬ 𝑋 ∈ V → (𝐴 ∩ (◡𝑅 “ {𝑋})) = ∅) |
| 10 | 1, 9 | eqtrid 2807 | 1 ⊢ (¬ 𝑋 ∈ V → Pred(𝑅, 𝐴, 𝑋) = ∅) |
| Colors of variables: wff setvar class |
| This proof depends on syntax axioms: ¬ wn 3 → wi 4 = wceq 1570 ∈ wcel 2145 Vcvv 3450 ∩ cin 3898 ∅c0 4279 {csn 4584 ◡ccnv 5654 “ cima 5658 Predcpred 6298 |
| This proof depends on axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1828 ax-4 1842 ax-5 1943 ax-6 2000 ax-7 2041 ax-8 2147 ax-9 2155 ax-ext 2732 ax-sep 5251 ax-pr 5398 |
| This proof depends on definitions: df-bi 210 df-an 402 df-or 862 df-3an 1105 df-tru 1573 df-fal 1583 df-ex 1813 df-sb 2100 df-clab 2739 df-cleq 2752 df-clel 2835 df-rab 3413 df-v 3452 df-dif 3902 df-un 3904 df-in 3906 df-ss 3916 df-nul 4280 df-if 4483 df-sn 4585 df-pr 4587 df-op 4591 df-br 5104 df-opab 5168 df-xp 5661 df-cnv 5663 df-dm 5665 df-rn 5666 df-res 5667 df-ima 5668 df-pred 6299 |
| This theorem is used by: predres 6337 |
| Copyright terms: Public domain | W3C validator |