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Mirrors > Home > MPE Home > Th. List > indstr | Structured version Visualization version GIF version |
Description: Strong Mathematical Induction for positive integers (inference schema). (Contributed by NM, 17-Aug-2001.) |
Ref | Expression |
---|---|
indstr.1 | ⊢ (𝑥 = 𝑦 → (𝜑 ↔ 𝜓)) |
indstr.2 | ⊢ (𝑥 ∈ ℕ → (∀𝑦 ∈ ℕ (𝑦 < 𝑥 → 𝜓) → 𝜑)) |
Ref | Expression |
---|---|
indstr | ⊢ (𝑥 ∈ ℕ → 𝜑) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | pm3.24 404 | . . . . . 6 ⊢ ¬ (𝜑 ∧ ¬ 𝜑) | |
2 | nnre 12214 | . . . . . . . . . . . . 13 ⊢ (𝑥 ∈ ℕ → 𝑥 ∈ ℝ) | |
3 | nnre 12214 | . . . . . . . . . . . . 13 ⊢ (𝑦 ∈ ℕ → 𝑦 ∈ ℝ) | |
4 | lenlt 11287 | . . . . . . . . . . . . 13 ⊢ ((𝑥 ∈ ℝ ∧ 𝑦 ∈ ℝ) → (𝑥 ≤ 𝑦 ↔ ¬ 𝑦 < 𝑥)) | |
5 | 2, 3, 4 | syl2an 597 | . . . . . . . . . . . 12 ⊢ ((𝑥 ∈ ℕ ∧ 𝑦 ∈ ℕ) → (𝑥 ≤ 𝑦 ↔ ¬ 𝑦 < 𝑥)) |
6 | 5 | imbi2d 341 | . . . . . . . . . . 11 ⊢ ((𝑥 ∈ ℕ ∧ 𝑦 ∈ ℕ) → ((¬ 𝜓 → 𝑥 ≤ 𝑦) ↔ (¬ 𝜓 → ¬ 𝑦 < 𝑥))) |
7 | con34b 316 | . . . . . . . . . . 11 ⊢ ((𝑦 < 𝑥 → 𝜓) ↔ (¬ 𝜓 → ¬ 𝑦 < 𝑥)) | |
8 | 6, 7 | bitr4di 289 | . . . . . . . . . 10 ⊢ ((𝑥 ∈ ℕ ∧ 𝑦 ∈ ℕ) → ((¬ 𝜓 → 𝑥 ≤ 𝑦) ↔ (𝑦 < 𝑥 → 𝜓))) |
9 | 8 | ralbidva 3176 | . . . . . . . . 9 ⊢ (𝑥 ∈ ℕ → (∀𝑦 ∈ ℕ (¬ 𝜓 → 𝑥 ≤ 𝑦) ↔ ∀𝑦 ∈ ℕ (𝑦 < 𝑥 → 𝜓))) |
10 | indstr.2 | . . . . . . . . 9 ⊢ (𝑥 ∈ ℕ → (∀𝑦 ∈ ℕ (𝑦 < 𝑥 → 𝜓) → 𝜑)) | |
11 | 9, 10 | sylbid 239 | . . . . . . . 8 ⊢ (𝑥 ∈ ℕ → (∀𝑦 ∈ ℕ (¬ 𝜓 → 𝑥 ≤ 𝑦) → 𝜑)) |
12 | 11 | anim2d 613 | . . . . . . 7 ⊢ (𝑥 ∈ ℕ → ((¬ 𝜑 ∧ ∀𝑦 ∈ ℕ (¬ 𝜓 → 𝑥 ≤ 𝑦)) → (¬ 𝜑 ∧ 𝜑))) |
13 | ancom 462 | . . . . . . 7 ⊢ ((¬ 𝜑 ∧ 𝜑) ↔ (𝜑 ∧ ¬ 𝜑)) | |
14 | 12, 13 | syl6ib 251 | . . . . . 6 ⊢ (𝑥 ∈ ℕ → ((¬ 𝜑 ∧ ∀𝑦 ∈ ℕ (¬ 𝜓 → 𝑥 ≤ 𝑦)) → (𝜑 ∧ ¬ 𝜑))) |
15 | 1, 14 | mtoi 198 | . . . . 5 ⊢ (𝑥 ∈ ℕ → ¬ (¬ 𝜑 ∧ ∀𝑦 ∈ ℕ (¬ 𝜓 → 𝑥 ≤ 𝑦))) |
16 | 15 | nrex 3075 | . . . 4 ⊢ ¬ ∃𝑥 ∈ ℕ (¬ 𝜑 ∧ ∀𝑦 ∈ ℕ (¬ 𝜓 → 𝑥 ≤ 𝑦)) |
17 | indstr.1 | . . . . . 6 ⊢ (𝑥 = 𝑦 → (𝜑 ↔ 𝜓)) | |
18 | 17 | notbid 318 | . . . . 5 ⊢ (𝑥 = 𝑦 → (¬ 𝜑 ↔ ¬ 𝜓)) |
19 | 18 | nnwos 12894 | . . . 4 ⊢ (∃𝑥 ∈ ℕ ¬ 𝜑 → ∃𝑥 ∈ ℕ (¬ 𝜑 ∧ ∀𝑦 ∈ ℕ (¬ 𝜓 → 𝑥 ≤ 𝑦))) |
20 | 16, 19 | mto 196 | . . 3 ⊢ ¬ ∃𝑥 ∈ ℕ ¬ 𝜑 |
21 | dfral2 3100 | . . 3 ⊢ (∀𝑥 ∈ ℕ 𝜑 ↔ ¬ ∃𝑥 ∈ ℕ ¬ 𝜑) | |
22 | 20, 21 | mpbir 230 | . 2 ⊢ ∀𝑥 ∈ ℕ 𝜑 |
23 | 22 | rspec 3248 | 1 ⊢ (𝑥 ∈ ℕ → 𝜑) |
Colors of variables: wff setvar class |
Syntax hints: ¬ wn 3 → wi 4 ↔ wb 205 ∧ wa 397 ∈ wcel 2107 ∀wral 3062 ∃wrex 3071 class class class wbr 5146 ℝcr 11104 < clt 11243 ≤ cle 11244 ℕcn 12207 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1798 ax-4 1812 ax-5 1914 ax-6 1972 ax-7 2012 ax-8 2109 ax-9 2117 ax-10 2138 ax-11 2155 ax-12 2172 ax-ext 2704 ax-sep 5297 ax-nul 5304 ax-pow 5361 ax-pr 5425 ax-un 7719 ax-cnex 11161 ax-resscn 11162 ax-1cn 11163 ax-icn 11164 ax-addcl 11165 ax-addrcl 11166 ax-mulcl 11167 ax-mulrcl 11168 ax-mulcom 11169 ax-addass 11170 ax-mulass 11171 ax-distr 11172 ax-i2m1 11173 ax-1ne0 11174 ax-1rid 11175 ax-rnegex 11176 ax-rrecex 11177 ax-cnre 11178 ax-pre-lttri 11179 ax-pre-lttrn 11180 ax-pre-ltadd 11181 ax-pre-mulgt0 11182 |
This theorem depends on definitions: df-bi 206 df-an 398 df-or 847 df-3or 1089 df-3an 1090 df-tru 1545 df-fal 1555 df-ex 1783 df-nf 1787 df-sb 2069 df-mo 2535 df-eu 2564 df-clab 2711 df-cleq 2725 df-clel 2811 df-nfc 2886 df-ne 2942 df-nel 3048 df-ral 3063 df-rex 3072 df-reu 3378 df-rab 3434 df-v 3477 df-sbc 3776 df-csb 3892 df-dif 3949 df-un 3951 df-in 3953 df-ss 3963 df-pss 3965 df-nul 4321 df-if 4527 df-pw 4602 df-sn 4627 df-pr 4629 df-op 4633 df-uni 4907 df-iun 4997 df-br 5147 df-opab 5209 df-mpt 5230 df-tr 5264 df-id 5572 df-eprel 5578 df-po 5586 df-so 5587 df-fr 5629 df-we 5631 df-xp 5680 df-rel 5681 df-cnv 5682 df-co 5683 df-dm 5684 df-rn 5685 df-res 5686 df-ima 5687 df-pred 6296 df-ord 6363 df-on 6364 df-lim 6365 df-suc 6366 df-iota 6491 df-fun 6541 df-fn 6542 df-f 6543 df-f1 6544 df-fo 6545 df-f1o 6546 df-fv 6547 df-riota 7359 df-ov 7406 df-oprab 7407 df-mpo 7408 df-om 7850 df-2nd 7970 df-frecs 8260 df-wrecs 8291 df-recs 8365 df-rdg 8404 df-er 8698 df-en 8935 df-dom 8936 df-sdom 8937 df-pnf 11245 df-mnf 11246 df-xr 11247 df-ltxr 11248 df-le 11249 df-sub 11441 df-neg 11442 df-nn 12208 df-n0 12468 df-z 12554 df-uz 12818 |
This theorem is referenced by: indstr2 12906 |
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