| Intuitionistic Logic Explorer |
< Previous
Next >
Nearby theorems |
||
| Mirrors > Home > ILE Home > Th. List > ge0nemnf | GIF version | ||
| Description: A nonnegative extended real is greater than negative infinity. (Contributed by Mario Carneiro, 20-Aug-2015.) |
| Ref | Expression |
|---|---|
| ge0nemnf | ⊢ ((𝐴 ∈ ℝ* ∧ 0 ≤ 𝐴) → 𝐴 ≠ -∞) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | ge0gtmnf 10175 | . 2 ⊢ ((𝐴 ∈ ℝ* ∧ 0 ≤ 𝐴) → -∞ < 𝐴) | |
| 2 | ngtmnft 10169 | . . . . 5 ⊢ (𝐴 ∈ ℝ* → (𝐴 = -∞ ↔ ¬ -∞ < 𝐴)) | |
| 3 | 2 | adantr 276 | . . . 4 ⊢ ((𝐴 ∈ ℝ* ∧ 0 ≤ 𝐴) → (𝐴 = -∞ ↔ ¬ -∞ < 𝐴)) |
| 4 | 3 | biimpd 144 | . . 3 ⊢ ((𝐴 ∈ ℝ* ∧ 0 ≤ 𝐴) → (𝐴 = -∞ → ¬ -∞ < 𝐴)) |
| 5 | 4 | necon2ad 2471 | . 2 ⊢ ((𝐴 ∈ ℝ* ∧ 0 ≤ 𝐴) → (-∞ < 𝐴 → 𝐴 ≠ -∞)) |
| 6 | 1, 5 | mpd 13 | 1 ⊢ ((𝐴 ∈ ℝ* ∧ 0 ≤ 𝐴) → 𝐴 ≠ -∞) |
| Colors of variables: wff set class |
| Syntax hints: ¬ wn 3 → wi 4 ∧ wa 104 ↔ wb 105 = wceq 1398 ∈ wcel 2205 ≠ wne 2414 class class class wbr 4114 0cc0 8143 -∞cmnf 8322 ℝ*cxr 8323 < clt 8324 ≤ cle 8325 |
| This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-ia1 106 ax-ia2 107 ax-ia3 108 ax-in1 619 ax-in2 620 ax-io 717 ax-5 1496 ax-7 1497 ax-gen 1498 ax-ie1 1542 ax-ie2 1543 ax-8 1553 ax-10 1554 ax-11 1555 ax-i12 1556 ax-bndl 1558 ax-4 1559 ax-17 1575 ax-i9 1579 ax-ial 1583 ax-i5r 1584 ax-13 2207 ax-14 2208 ax-ext 2216 ax-sep 4233 ax-pow 4292 ax-pr 4327 ax-un 4559 ax-setind 4664 ax-cnex 8234 ax-resscn 8235 ax-1re 8237 ax-addrcl 8240 ax-rnegex 8252 ax-pre-ltirr 8255 ax-pre-ltwlin 8256 ax-pre-lttrn 8257 |
| This theorem depends on definitions: df-bi 117 df-3or 1006 df-3an 1007 df-tru 1401 df-fal 1404 df-nf 1510 df-sb 1812 df-eu 2085 df-mo 2086 df-clab 2221 df-cleq 2227 df-clel 2230 df-nfc 2375 df-ne 2415 df-nel 2510 df-ral 2527 df-rex 2528 df-rab 2531 df-v 2817 df-dif 3216 df-un 3218 df-in 3220 df-ss 3227 df-pw 3676 df-sn 3700 df-pr 3701 df-op 3703 df-uni 3920 df-br 4115 df-opab 4177 df-po 4422 df-iso 4423 df-xp 4760 df-cnv 4762 df-pnf 8326 df-mnf 8327 df-xr 8328 df-ltxr 8329 df-le 8330 |
| This theorem is referenced by: xlesubadd 10235 xrbdtri 11986 isxmet2d 15325 xmetrtri 15353 xblpnfps 15375 xblpnf 15376 xblss2ps 15381 xblss2 15382 |
| Copyright terms: Public domain | W3C validator |