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| Mirrors > Home > MPE Home > Th. List > Mathboxes > presucmap | Structured version Visualization version GIF version | ||
| Description: pre is really a predecessor (when it should be). This correctness theorem for pre makes it usable in proofs without unfolding ℩. This theorem gives one witness; preuniqval 38518 gives it is the only one. (Contributed by Peter Mazsa, 12-Jan-2026.) |
| Ref | Expression |
|---|---|
| presucmap | ⊢ (𝑁 ∈ ran SucMap → pre 𝑁 SucMap 𝑁) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | dfpre2 38500 | . . 3 ⊢ (𝑁 ∈ ran SucMap → pre 𝑁 = (℩𝑚𝑚 SucMap 𝑁)) | |
| 2 | 1 | eqcomd 2737 | . 2 ⊢ (𝑁 ∈ ran SucMap → (℩𝑚𝑚 SucMap 𝑁) = pre 𝑁) |
| 3 | preex 38514 | . . 3 ⊢ pre 𝑁 ∈ V | |
| 4 | eupre2 38515 | . . . 4 ⊢ (𝑁 ∈ ran SucMap → (𝑁 ∈ ran SucMap ↔ ∃!𝑚 𝑚 SucMap 𝑁)) | |
| 5 | 4 | ibi 267 | . . 3 ⊢ (𝑁 ∈ ran SucMap → ∃!𝑚 𝑚 SucMap 𝑁) |
| 6 | breq1 5092 | . . . 4 ⊢ (𝑚 = pre 𝑁 → (𝑚 SucMap 𝑁 ↔ pre 𝑁 SucMap 𝑁)) | |
| 7 | 6 | iota2 6470 | . . 3 ⊢ (( pre 𝑁 ∈ V ∧ ∃!𝑚 𝑚 SucMap 𝑁) → ( pre 𝑁 SucMap 𝑁 ↔ (℩𝑚𝑚 SucMap 𝑁) = pre 𝑁)) |
| 8 | 3, 5, 7 | sylancr 587 | . 2 ⊢ (𝑁 ∈ ran SucMap → ( pre 𝑁 SucMap 𝑁 ↔ (℩𝑚𝑚 SucMap 𝑁) = pre 𝑁)) |
| 9 | 2, 8 | mpbird 257 | 1 ⊢ (𝑁 ∈ ran SucMap → pre 𝑁 SucMap 𝑁) |
| Colors of variables: wff setvar class |
| Syntax hints: → wi 4 ↔ wb 206 = wceq 1541 ∈ wcel 2111 ∃!weu 2563 Vcvv 3436 class class class wbr 5089 ran crn 5615 ℩cio 6435 SucMap csucmap 38227 pre cpre 38229 |
| 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 2113 ax-9 2121 ax-10 2144 ax-11 2160 ax-12 2180 ax-ext 2703 ax-sep 5232 ax-nul 5242 ax-pr 5368 ax-un 7668 ax-reg 9478 |
| 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 2535 df-eu 2564 df-clab 2710 df-cleq 2723 df-clel 2806 df-nfc 2881 df-ne 2929 df-ral 3048 df-rex 3057 df-rab 3396 df-v 3438 df-dif 3900 df-un 3902 df-in 3904 df-ss 3914 df-nul 4281 df-if 4473 df-pw 4549 df-sn 4574 df-pr 4576 df-op 4580 df-uni 4857 df-br 5090 df-opab 5152 df-eprel 5514 df-fr 5567 df-xp 5620 df-cnv 5622 df-dm 5624 df-rn 5625 df-res 5626 df-ima 5627 df-pred 6248 df-suc 6312 df-iota 6437 df-sucmap 38485 df-pre 38498 |
| This theorem is referenced by: preuniqval 38518 sucpre 38519 |
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