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| 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 10101 | . 2 ⊢ ((𝐴 ∈ ℝ* ∧ 0 ≤ 𝐴) → -∞ < 𝐴) | |
| 2 | ngtmnft 10095 | . . . . 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 2460 | . 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 2202 ≠ wne 2403 class class class wbr 4093 0cc0 8075 -∞cmnf 8255 ℝ*cxr 8256 < clt 8257 ≤ cle 8258 |
| 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 2204 ax-14 2205 ax-ext 2213 ax-sep 4212 ax-pow 4270 ax-pr 4305 ax-un 4536 ax-setind 4641 ax-cnex 8166 ax-resscn 8167 ax-1re 8169 ax-addrcl 8172 ax-rnegex 8184 ax-pre-ltirr 8187 ax-pre-ltwlin 8188 ax-pre-lttrn 8189 |
| 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 1811 df-eu 2082 df-mo 2083 df-clab 2218 df-cleq 2224 df-clel 2227 df-nfc 2364 df-ne 2404 df-nel 2499 df-ral 2516 df-rex 2517 df-rab 2520 df-v 2805 df-dif 3203 df-un 3205 df-in 3207 df-ss 3214 df-pw 3658 df-sn 3679 df-pr 3680 df-op 3682 df-uni 3899 df-br 4094 df-opab 4156 df-po 4399 df-iso 4400 df-xp 4737 df-cnv 4739 df-pnf 8259 df-mnf 8260 df-xr 8261 df-ltxr 8262 df-le 8263 |
| This theorem is referenced by: xlesubadd 10161 xrbdtri 11897 isxmet2d 15139 xmetrtri 15167 xblpnfps 15189 xblpnf 15190 xblss2ps 15195 xblss2 15196 |
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