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| Mirrors > Home > MPE Home > Th. List > Mathboxes > presuc | Structured version Visualization version GIF version | ||
| Description: pre is a left-inverse of suc. This theorem gives a clean rewrite rule that eliminates pre on explicit successors. (Contributed by Peter Mazsa, 12-Jan-2026.) |
| Ref | Expression |
|---|---|
| presuc | ⊢ (𝑀 ∈ 𝑉 → pre suc 𝑀 = 𝑀) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | sucmapsuc 38856 | . . 3 ⊢ (𝑀 ∈ 𝑉 → 𝑀 SucMap suc 𝑀) | |
| 2 | relsucmap 38834 | . . . . 5 ⊢ Rel SucMap | |
| 3 | 2 | relelrni 5891 | . . . 4 ⊢ (𝑀 SucMap suc 𝑀 → suc 𝑀 ∈ ran SucMap ) |
| 4 | df-succl 38836 | . . . 4 ⊢ Suc = ran SucMap | |
| 5 | 3, 4 | eleqtrrdi 2850 | . . 3 ⊢ (𝑀 SucMap suc 𝑀 → suc 𝑀 ∈ Suc ) |
| 6 | sucpre 38864 | . . 3 ⊢ (suc 𝑀 ∈ Suc → suc pre suc 𝑀 = suc 𝑀) | |
| 7 | 1, 5, 6 | 3syl 18 | . 2 ⊢ (𝑀 ∈ 𝑉 → suc pre suc 𝑀 = suc 𝑀) |
| 8 | suc11reg 9531 | . 2 ⊢ (suc pre suc 𝑀 = suc 𝑀 ↔ pre suc 𝑀 = 𝑀) | |
| 9 | 7, 8 | sylib 219 | 1 ⊢ (𝑀 ∈ 𝑉 → pre suc 𝑀 = 𝑀) |
| Colors of variables: wff setvar class |
| Syntax hints: → wi 4 = wceq 1547 ∈ wcel 2119 class class class wbr 5072 ran crn 5619 suc csuc 6312 SucMap csucmap 38545 Suc csuccl 38546 pre cpre 38547 |
| This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1802 ax-4 1816 ax-5 1917 ax-6 1974 ax-7 2015 ax-8 2121 ax-9 2129 ax-10 2152 ax-11 2168 ax-12 2189 ax-ext 2711 ax-sep 5218 ax-nul 5228 ax-pr 5362 ax-un 7678 ax-reg 9497 |
| This theorem depends on definitions: df-bi 208 df-an 397 df-or 854 df-3an 1094 df-tru 1550 df-fal 1560 df-ex 1787 df-nf 1791 df-sb 2074 df-mo 2543 df-eu 2573 df-clab 2718 df-cleq 2731 df-clel 2814 df-nfc 2888 df-ne 2935 df-ral 3054 df-rex 3064 df-rab 3392 df-v 3433 df-dif 3886 df-un 3888 df-in 3890 df-ss 3900 df-nul 4262 df-if 4455 df-pw 4531 df-sn 4556 df-pr 4558 df-op 4562 df-uni 4839 df-br 5073 df-opab 5135 df-eprel 5518 df-fr 5571 df-xp 5624 df-rel 5625 df-cnv 5626 df-dm 5628 df-rn 5629 df-res 5630 df-ima 5631 df-pred 6252 df-suc 6316 df-iota 6441 df-sucmap 38829 df-succl 38836 df-pre 38842 |
| This theorem is referenced by: (None) |
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