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Mirrors > Home > ILE Home > Th. List > mnfnre | GIF version |
Description: Minus infinity is not a real number. (Contributed by NM, 13-Oct-2005.) |
Ref | Expression |
---|---|
mnfnre | ⊢ -∞ ∉ ℝ |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | cnex 7768 | . . . . 5 ⊢ ℂ ∈ V | |
2 | 2pwuninelg 6188 | . . . . 5 ⊢ (ℂ ∈ V → ¬ 𝒫 𝒫 ∪ ℂ ∈ ℂ) | |
3 | 1, 2 | ax-mp 5 | . . . 4 ⊢ ¬ 𝒫 𝒫 ∪ ℂ ∈ ℂ |
4 | df-mnf 7827 | . . . . . 6 ⊢ -∞ = 𝒫 +∞ | |
5 | df-pnf 7826 | . . . . . . 7 ⊢ +∞ = 𝒫 ∪ ℂ | |
6 | 5 | pweqi 3519 | . . . . . 6 ⊢ 𝒫 +∞ = 𝒫 𝒫 ∪ ℂ |
7 | 4, 6 | eqtri 2161 | . . . . 5 ⊢ -∞ = 𝒫 𝒫 ∪ ℂ |
8 | 7 | eleq1i 2206 | . . . 4 ⊢ (-∞ ∈ ℂ ↔ 𝒫 𝒫 ∪ ℂ ∈ ℂ) |
9 | 3, 8 | mtbir 661 | . . 3 ⊢ ¬ -∞ ∈ ℂ |
10 | recn 7777 | . . 3 ⊢ (-∞ ∈ ℝ → -∞ ∈ ℂ) | |
11 | 9, 10 | mto 652 | . 2 ⊢ ¬ -∞ ∈ ℝ |
12 | 11 | nelir 2407 | 1 ⊢ -∞ ∉ ℝ |
Colors of variables: wff set class |
Syntax hints: ¬ wn 3 ∈ wcel 1481 ∉ wnel 2404 Vcvv 2689 𝒫 cpw 3515 ∪ cuni 3744 ℂcc 7642 ℝcr 7643 +∞cpnf 7821 -∞cmnf 7822 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-ia1 105 ax-ia2 106 ax-ia3 107 ax-in1 604 ax-in2 605 ax-io 699 ax-5 1424 ax-7 1425 ax-gen 1426 ax-ie1 1470 ax-ie2 1471 ax-8 1483 ax-10 1484 ax-11 1485 ax-i12 1486 ax-bndl 1487 ax-4 1488 ax-17 1507 ax-i9 1511 ax-ial 1515 ax-i5r 1516 ax-ext 2122 ax-setind 4460 ax-cnex 7735 ax-resscn 7736 |
This theorem depends on definitions: df-bi 116 df-3an 965 df-tru 1335 df-nf 1438 df-sb 1737 df-clab 2127 df-cleq 2133 df-clel 2136 df-nfc 2271 df-nel 2405 df-ral 2422 df-v 2691 df-dif 3078 df-un 3080 df-in 3082 df-ss 3089 df-pw 3517 df-sn 3538 df-pr 3539 df-uni 3745 df-pnf 7826 df-mnf 7827 |
This theorem is referenced by: renemnf 7838 xrltnr 9596 nltmnf 9604 |
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