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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 38827 | . . 3 ⊢ (𝑀 ∈ 𝑉 → 𝑀 SucMap suc 𝑀) | |
| 2 | relsucmap 38805 | . . . . 5 ⊢ Rel SucMap | |
| 3 | 2 | relelrni 5899 | . . . 4 ⊢ (𝑀 SucMap suc 𝑀 → suc 𝑀 ∈ ran SucMap ) |
| 4 | df-succl 38807 | . . . 4 ⊢ Suc = ran SucMap | |
| 5 | 3, 4 | eleqtrrdi 2848 | . . 3 ⊢ (𝑀 SucMap suc 𝑀 → suc 𝑀 ∈ Suc ) |
| 6 | sucpre 38835 | . . 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 9534 | . 2 ⊢ (suc pre suc 𝑀 = suc 𝑀 ↔ pre suc 𝑀 = 𝑀) | |
| 9 | 7, 8 | sylib 218 | 1 ⊢ (𝑀 ∈ 𝑉 → pre suc 𝑀 = 𝑀) |
| Colors of variables: wff setvar class |
| Syntax hints: → wi 4 = wceq 1542 ∈ wcel 2114 class class class wbr 5086 ran crn 5626 suc csuc 6320 SucMap csucmap 38516 Suc csuccl 38517 pre cpre 38518 |
| This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1797 ax-4 1811 ax-5 1912 ax-6 1969 ax-7 2010 ax-8 2116 ax-9 2124 ax-10 2147 ax-11 2163 ax-12 2185 ax-ext 2709 ax-sep 5232 ax-nul 5242 ax-pr 5371 ax-un 7683 ax-reg 9501 |
| This theorem depends on definitions: df-bi 207 df-an 396 df-or 849 df-3an 1089 df-tru 1545 df-fal 1555 df-ex 1782 df-nf 1786 df-sb 2069 df-mo 2540 df-eu 2570 df-clab 2716 df-cleq 2729 df-clel 2812 df-nfc 2886 df-ne 2934 df-ral 3053 df-rex 3063 df-rab 3391 df-v 3432 df-dif 3893 df-un 3895 df-in 3897 df-ss 3907 df-nul 4275 df-if 4468 df-pw 4544 df-sn 4569 df-pr 4571 df-op 4575 df-uni 4852 df-br 5087 df-opab 5149 df-eprel 5525 df-fr 5578 df-xp 5631 df-rel 5632 df-cnv 5633 df-dm 5635 df-rn 5636 df-res 5637 df-ima 5638 df-pred 6260 df-suc 6324 df-iota 6449 df-sucmap 38800 df-succl 38807 df-pre 38813 |
| This theorem is referenced by: (None) |
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