![]() |
Metamath Proof Explorer |
< Previous
Next >
Nearby theorems |
|
Mirrors > Home > MPE Home > Th. List > degltlem1 | Structured version Visualization version GIF version |
Description: Theorem on arithmetic of extended reals useful for degrees. (Contributed by Stefan O'Rear, 23-Mar-2015.) |
Ref | Expression |
---|---|
degltlem1 | ⊢ ((𝑋 ∈ (ℕ0 ∪ {-∞}) ∧ 𝑌 ∈ ℤ) → (𝑋 < 𝑌 ↔ 𝑋 ≤ (𝑌 − 1))) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | elun 4163 | . 2 ⊢ (𝑋 ∈ (ℕ0 ∪ {-∞}) ↔ (𝑋 ∈ ℕ0 ∨ 𝑋 ∈ {-∞})) | |
2 | nn0z 12636 | . . . 4 ⊢ (𝑋 ∈ ℕ0 → 𝑋 ∈ ℤ) | |
3 | zltlem1 12668 | . . . 4 ⊢ ((𝑋 ∈ ℤ ∧ 𝑌 ∈ ℤ) → (𝑋 < 𝑌 ↔ 𝑋 ≤ (𝑌 − 1))) | |
4 | 2, 3 | sylan 580 | . . 3 ⊢ ((𝑋 ∈ ℕ0 ∧ 𝑌 ∈ ℤ) → (𝑋 < 𝑌 ↔ 𝑋 ≤ (𝑌 − 1))) |
5 | zre 12615 | . . . . . . 7 ⊢ (𝑌 ∈ ℤ → 𝑌 ∈ ℝ) | |
6 | 5 | mnfltd 13164 | . . . . . 6 ⊢ (𝑌 ∈ ℤ → -∞ < 𝑌) |
7 | peano2zm 12658 | . . . . . . . . 9 ⊢ (𝑌 ∈ ℤ → (𝑌 − 1) ∈ ℤ) | |
8 | 7 | zred 12720 | . . . . . . . 8 ⊢ (𝑌 ∈ ℤ → (𝑌 − 1) ∈ ℝ) |
9 | 8 | rexrd 11309 | . . . . . . 7 ⊢ (𝑌 ∈ ℤ → (𝑌 − 1) ∈ ℝ*) |
10 | mnfle 13174 | . . . . . . 7 ⊢ ((𝑌 − 1) ∈ ℝ* → -∞ ≤ (𝑌 − 1)) | |
11 | 9, 10 | syl 17 | . . . . . 6 ⊢ (𝑌 ∈ ℤ → -∞ ≤ (𝑌 − 1)) |
12 | 6, 11 | 2thd 265 | . . . . 5 ⊢ (𝑌 ∈ ℤ → (-∞ < 𝑌 ↔ -∞ ≤ (𝑌 − 1))) |
13 | elsni 4648 | . . . . . 6 ⊢ (𝑋 ∈ {-∞} → 𝑋 = -∞) | |
14 | breq1 5151 | . . . . . . 7 ⊢ (𝑋 = -∞ → (𝑋 < 𝑌 ↔ -∞ < 𝑌)) | |
15 | breq1 5151 | . . . . . . 7 ⊢ (𝑋 = -∞ → (𝑋 ≤ (𝑌 − 1) ↔ -∞ ≤ (𝑌 − 1))) | |
16 | 14, 15 | bibi12d 345 | . . . . . 6 ⊢ (𝑋 = -∞ → ((𝑋 < 𝑌 ↔ 𝑋 ≤ (𝑌 − 1)) ↔ (-∞ < 𝑌 ↔ -∞ ≤ (𝑌 − 1)))) |
17 | 13, 16 | syl 17 | . . . . 5 ⊢ (𝑋 ∈ {-∞} → ((𝑋 < 𝑌 ↔ 𝑋 ≤ (𝑌 − 1)) ↔ (-∞ < 𝑌 ↔ -∞ ≤ (𝑌 − 1)))) |
18 | 12, 17 | syl5ibrcom 247 | . . . 4 ⊢ (𝑌 ∈ ℤ → (𝑋 ∈ {-∞} → (𝑋 < 𝑌 ↔ 𝑋 ≤ (𝑌 − 1)))) |
19 | 18 | impcom 407 | . . 3 ⊢ ((𝑋 ∈ {-∞} ∧ 𝑌 ∈ ℤ) → (𝑋 < 𝑌 ↔ 𝑋 ≤ (𝑌 − 1))) |
20 | 4, 19 | jaoian 958 | . 2 ⊢ (((𝑋 ∈ ℕ0 ∨ 𝑋 ∈ {-∞}) ∧ 𝑌 ∈ ℤ) → (𝑋 < 𝑌 ↔ 𝑋 ≤ (𝑌 − 1))) |
21 | 1, 20 | sylanb 581 | 1 ⊢ ((𝑋 ∈ (ℕ0 ∪ {-∞}) ∧ 𝑌 ∈ ℤ) → (𝑋 < 𝑌 ↔ 𝑋 ≤ (𝑌 − 1))) |
Colors of variables: wff setvar class |
Syntax hints: → wi 4 ↔ wb 206 ∧ wa 395 ∨ wo 847 = wceq 1537 ∈ wcel 2106 ∪ cun 3961 {csn 4631 class class class wbr 5148 (class class class)co 7431 1c1 11154 -∞cmnf 11291 ℝ*cxr 11292 < clt 11293 ≤ cle 11294 − cmin 11490 ℕ0cn0 12524 ℤcz 12611 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1792 ax-4 1806 ax-5 1908 ax-6 1965 ax-7 2005 ax-8 2108 ax-9 2116 ax-10 2139 ax-11 2155 ax-12 2175 ax-ext 2706 ax-sep 5302 ax-nul 5312 ax-pow 5371 ax-pr 5438 ax-un 7754 ax-cnex 11209 ax-resscn 11210 ax-1cn 11211 ax-icn 11212 ax-addcl 11213 ax-addrcl 11214 ax-mulcl 11215 ax-mulrcl 11216 ax-mulcom 11217 ax-addass 11218 ax-mulass 11219 ax-distr 11220 ax-i2m1 11221 ax-1ne0 11222 ax-1rid 11223 ax-rnegex 11224 ax-rrecex 11225 ax-cnre 11226 ax-pre-lttri 11227 ax-pre-lttrn 11228 ax-pre-ltadd 11229 ax-pre-mulgt0 11230 |
This theorem depends on definitions: df-bi 207 df-an 396 df-or 848 df-3or 1087 df-3an 1088 df-tru 1540 df-fal 1550 df-ex 1777 df-nf 1781 df-sb 2063 df-mo 2538 df-eu 2567 df-clab 2713 df-cleq 2727 df-clel 2814 df-nfc 2890 df-ne 2939 df-nel 3045 df-ral 3060 df-rex 3069 df-reu 3379 df-rab 3434 df-v 3480 df-sbc 3792 df-csb 3909 df-dif 3966 df-un 3968 df-in 3970 df-ss 3980 df-pss 3983 df-nul 4340 df-if 4532 df-pw 4607 df-sn 4632 df-pr 4634 df-op 4638 df-uni 4913 df-iun 4998 df-br 5149 df-opab 5211 df-mpt 5232 df-tr 5266 df-id 5583 df-eprel 5589 df-po 5597 df-so 5598 df-fr 5641 df-we 5643 df-xp 5695 df-rel 5696 df-cnv 5697 df-co 5698 df-dm 5699 df-rn 5700 df-res 5701 df-ima 5702 df-pred 6323 df-ord 6389 df-on 6390 df-lim 6391 df-suc 6392 df-iota 6516 df-fun 6565 df-fn 6566 df-f 6567 df-f1 6568 df-fo 6569 df-f1o 6570 df-fv 6571 df-riota 7388 df-ov 7434 df-oprab 7435 df-mpo 7436 df-om 7888 df-2nd 8014 df-frecs 8305 df-wrecs 8336 df-recs 8410 df-rdg 8449 df-er 8744 df-en 8985 df-dom 8986 df-sdom 8987 df-pnf 11295 df-mnf 11296 df-xr 11297 df-ltxr 11298 df-le 11299 df-sub 11492 df-neg 11493 df-nn 12265 df-n0 12525 df-z 12612 |
This theorem is referenced by: degltp1le 26127 ply1divex 26191 algextdeglem8 33730 |
Copyright terms: Public domain | W3C validator |