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| 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 2734 | . . 3 ⊢ setrecs(𝐹) = setrecs(𝐹) | |
| 2 | ss0 4352 | . . . . 5 ⊢ (𝑥 ⊆ ∅ → 𝑥 = ∅) | |
| 3 | fveq2 6832 | . . . . . . 7 ⊢ (𝑥 = ∅ → (𝐹‘𝑥) = (𝐹‘∅)) | |
| 4 | 0setrec.1 | . . . . . . 7 ⊢ (𝜑 → (𝐹‘∅) = ∅) | |
| 5 | 3, 4 | sylan9eqr 2791 | . . . . . 6 ⊢ ((𝜑 ∧ 𝑥 = ∅) → (𝐹‘𝑥) = ∅) |
| 6 | 5 | ex 412 | . . . . 5 ⊢ (𝜑 → (𝑥 = ∅ → (𝐹‘𝑥) = ∅)) |
| 7 | eqimss 3990 | . . . . 5 ⊢ ((𝐹‘𝑥) = ∅ → (𝐹‘𝑥) ⊆ ∅) | |
| 8 | 2, 6, 7 | syl56 36 | . . . 4 ⊢ (𝜑 → (𝑥 ⊆ ∅ → (𝐹‘𝑥) ⊆ ∅)) |
| 9 | 8 | alrimiv 1928 | . . 3 ⊢ (𝜑 → ∀𝑥(𝑥 ⊆ ∅ → (𝐹‘𝑥) ⊆ ∅)) |
| 10 | 1, 9 | setrec2v 49883 | . 2 ⊢ (𝜑 → setrecs(𝐹) ⊆ ∅) |
| 11 | ss0 4352 | . 2 ⊢ (setrecs(𝐹) ⊆ ∅ → setrecs(𝐹) = ∅) | |
| 12 | 10, 11 | syl 17 | 1 ⊢ (𝜑 → setrecs(𝐹) = ∅) |
| Colors of variables: wff setvar class |
| Syntax hints: → wi 4 = wceq 1541 ⊆ wss 3899 ∅c0 4283 ‘cfv 6490 setrecscsetrecs 49870 |
| This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1796 ax-4 1810 ax-5 1911 ax-6 1968 ax-7 2009 ax-8 2115 ax-9 2123 ax-10 2146 ax-11 2162 ax-12 2182 ax-ext 2706 ax-rep 5222 ax-sep 5239 ax-nul 5249 ax-pow 5308 ax-pr 5375 ax-un 7678 |
| This theorem depends on definitions: df-bi 207 df-an 396 df-or 848 df-3an 1088 df-tru 1544 df-fal 1554 df-ex 1781 df-nf 1785 df-sb 2068 df-mo 2537 df-eu 2567 df-clab 2713 df-cleq 2726 df-clel 2809 df-nfc 2883 df-ne 2931 df-ral 3050 df-rex 3059 df-rab 3398 df-v 3440 df-dif 3902 df-un 3904 df-in 3906 df-ss 3916 df-nul 4284 df-if 4478 df-pw 4554 df-sn 4579 df-pr 4581 df-op 4585 df-uni 4862 df-br 5097 df-opab 5159 df-id 5517 df-xp 5628 df-rel 5629 df-cnv 5630 df-co 5631 df-dm 5632 df-rn 5633 df-res 5634 df-ima 5635 df-iota 6446 df-fun 6492 df-fv 6498 df-setrecs 49871 |
| This theorem is referenced by: (None) |
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