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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 6301 | . 2 ⊢ Pred(𝑅, 𝐴, 𝑋) = (𝐴 ∩ (◡𝑅 “ {𝑋})) | |
2 | snprc 4722 | . . . . . . 7 ⊢ (¬ 𝑋 ∈ V ↔ {𝑋} = ∅) | |
3 | 2 | biimpi 215 | . . . . . 6 ⊢ (¬ 𝑋 ∈ V → {𝑋} = ∅) |
4 | 3 | imaeq2d 6060 | . . . . 5 ⊢ (¬ 𝑋 ∈ V → (◡𝑅 “ {𝑋}) = (◡𝑅 “ ∅)) |
5 | ima0 6077 | . . . . 5 ⊢ (◡𝑅 “ ∅) = ∅ | |
6 | 4, 5 | eqtrdi 2789 | . . . 4 ⊢ (¬ 𝑋 ∈ V → (◡𝑅 “ {𝑋}) = ∅) |
7 | 6 | ineq2d 4213 | . . 3 ⊢ (¬ 𝑋 ∈ V → (𝐴 ∩ (◡𝑅 “ {𝑋})) = (𝐴 ∩ ∅)) |
8 | in0 4392 | . . 3 ⊢ (𝐴 ∩ ∅) = ∅ | |
9 | 7, 8 | eqtrdi 2789 | . 2 ⊢ (¬ 𝑋 ∈ V → (𝐴 ∩ (◡𝑅 “ {𝑋})) = ∅) |
10 | 1, 9 | eqtrid 2785 | 1 ⊢ (¬ 𝑋 ∈ V → Pred(𝑅, 𝐴, 𝑋) = ∅) |
Colors of variables: wff setvar class |
Syntax hints: ¬ wn 3 → wi 4 = wceq 1542 ∈ wcel 2107 Vcvv 3475 ∩ cin 3948 ∅c0 4323 {csn 4629 ◡ccnv 5676 “ cima 5680 Predcpred 6300 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1798 ax-4 1812 ax-5 1914 ax-6 1972 ax-7 2012 ax-8 2109 ax-9 2117 ax-10 2138 ax-11 2155 ax-12 2172 ax-ext 2704 ax-sep 5300 ax-nul 5307 ax-pr 5428 |
This theorem depends on definitions: df-bi 206 df-an 398 df-or 847 df-3an 1090 df-tru 1545 df-fal 1555 df-ex 1783 df-nf 1787 df-sb 2069 df-clab 2711 df-cleq 2725 df-clel 2811 df-rab 3434 df-v 3477 df-dif 3952 df-un 3954 df-in 3956 df-ss 3966 df-nul 4324 df-if 4530 df-sn 4630 df-pr 4632 df-op 4636 df-br 5150 df-opab 5212 df-xp 5683 df-cnv 5685 df-dm 5687 df-rn 5688 df-res 5689 df-ima 5690 df-pred 6301 |
This theorem is referenced by: predres 6341 |
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