| Mathbox for Emmett Weisz |
< Previous
Next >
Nearby theorems |
||
| Mirrors > Home > MPE Home > Th. List > Mathboxes > 0setrec | Structured version Visualization version GIF version | ||
| Description: If a function sends the empty set to itself, the function will not recursively generate any sets, regardless of its other values. (Contributed by Emmett Weisz, 23-Jun-2021.) |
| Ref | Expression |
|---|---|
| 0setrec.1 | ⊢ (𝜑 → (𝐹‘∅) = ∅) |
| Ref | Expression |
|---|---|
| 0setrec | ⊢ (𝜑 → setrecs(𝐹) = ∅) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | eqid 2763 | . . 3 ⊢ setrecs(𝐹) = setrecs(𝐹) | |
| 2 | ss0 4359 | . . . . 5 ⊢ (𝑥 ⊆ ∅ → 𝑥 = ∅) | |
| 3 | fveq2 6881 | . . . . . . 7 ⊢ (𝑥 = ∅ → (𝐹‘𝑥) = (𝐹‘∅)) | |
| 4 | 0setrec.1 | . . . . . . 7 ⊢ (𝜑 → (𝐹‘∅) = ∅) | |
| 5 | 3, 4 | sylan9eqr 2820 | . . . . . 6 ⊢ ((𝜑 ∧ 𝑥 = ∅) → (𝐹‘𝑥) = ∅) |
| 6 | 5 | ex 417 | . . . . 5 ⊢ (𝜑 → (𝑥 = ∅ → (𝐹‘𝑥) = ∅)) |
| 7 | eqimss 3995 | . . . . 5 ⊢ ((𝐹‘𝑥) = ∅ → (𝐹‘𝑥) ⊆ ∅) | |
| 8 | 2, 6, 7 | syl56 37 | . . . 4 ⊢ (𝜑 → (𝑥 ⊆ ∅ → (𝐹‘𝑥) ⊆ ∅)) |
| 9 | 8 | alrimiv 1957 | . . 3 ⊢ (𝜑 → ∀𝑥(𝑥 ⊆ ∅ → (𝐹‘𝑥) ⊆ ∅)) |
| 10 | 1, 9 | setrec2v 50494 | . 2 ⊢ (𝜑 → setrecs(𝐹) ⊆ ∅) |
| 11 | ss0 4359 | . 2 ⊢ (setrecs(𝐹) ⊆ ∅ → setrecs(𝐹) = ∅) | |
| 12 | 10, 11 | syl 18 | 1 ⊢ (𝜑 → setrecs(𝐹) = ∅) |
| Colors of variables: wff setvar class |
| Syntax hints: → wi 4 = wceq 1570 ⊆ wss 3905 ∅c0 4286 ‘cfv 6536 setrecscsetrecs 50481 |
| This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1825 ax-4 1839 ax-5 1940 ax-6 1997 ax-7 2038 ax-8 2145 ax-9 2153 ax-10 2176 ax-11 2192 ax-12 2213 ax-ext 2735 ax-rep 5238 ax-sep 5257 ax-nul 5269 ax-pow 5336 ax-pr 5404 ax-un 7732 |
| This theorem depends on definitions: df-bi 210 df-an 401 df-or 861 df-3an 1105 df-tru 1573 df-fal 1583 df-ex 1810 df-nf 1814 df-sb 2097 df-mo 2567 df-eu 2597 df-clab 2742 df-cleq 2755 df-clel 2838 df-nfc 2912 df-ne 2959 df-ral 3080 df-rex 3090 df-rab 3417 df-v 3457 df-dif 3908 df-un 3910 df-in 3912 df-ss 3922 df-nul 4287 df-if 4488 df-pw 4564 df-sn 4590 df-pr 4592 df-op 4596 df-uni 4873 df-br 5110 df-opab 5174 df-id 5556 df-xp 5667 df-rel 5668 df-cnv 5669 df-co 5670 df-dm 5671 df-rn 5672 df-res 5673 df-ima 5674 df-iota 6492 df-fun 6538 df-fv 6544 df-setrecs 50482 |
| This theorem is referenced by: (None) |
| Copyright terms: Public domain | W3C validator |