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| Mirrors > Home > MPE Home > Th. List > pred0 | Structured version Visualization version GIF version | ||
| Description: The predecessor class over ∅ is always ∅. (Contributed by Scott Fenton, 16-Apr-2011.) (Proof shortened by AV, 11-Jun-2021.) |
| Ref | Expression |
|---|---|
| pred0 | ⊢ Pred(𝑅, ∅, 𝑋) = ∅ |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | df-pred 6325 | . 2 ⊢ Pred(𝑅, ∅, 𝑋) = (∅ ∩ (◡𝑅 “ {𝑋})) | |
| 2 | 0in 4350 | . 2 ⊢ (∅ ∩ (◡𝑅 “ {𝑋})) = ∅ | |
| 3 | 1, 2 | eqtri 2786 | 1 ⊢ Pred(𝑅, ∅, 𝑋) = ∅ |
| Colors of variables: wff setvar class |
| This proof depends on syntax axioms: = wceq 1570 ∩ cin 4092 ∅c0 4281 {csn 4588 ◡ccnv 5655 “ cima 5659 Predcpred 6324 |
| 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 1945 ax-6 2002 ax-7 2043 ax-8 2149 ax-9 2157 ax-ext 2735 |
| This proof depends on definitions: df-bi 210 df-an 402 df-tru 1573 df-fal 1583 df-ex 1813 df-sb 2102 df-clab 2742 df-cleq 2755 df-clel 2839 df-rab 3417 df-v 3456 df-dif 4050 df-in 4094 df-nul 4282 df-pred 6325 |
| This theorem is used by: (None) |
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