![]() |
Intuitionistic Logic Explorer |
< Previous
Next >
Nearby theorems |
|
Mirrors > Home > ILE Home > Th. List > mnfltpnf | GIF version |
Description: Minus infinity is less than plus infinity. (Contributed by NM, 14-Oct-2005.) |
Ref | Expression |
---|---|
mnfltpnf | ⊢ -∞ < +∞ |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | eqid 2140 | . . . 4 ⊢ -∞ = -∞ | |
2 | eqid 2140 | . . . 4 ⊢ +∞ = +∞ | |
3 | olc 701 | . . . 4 ⊢ ((-∞ = -∞ ∧ +∞ = +∞) → (((-∞ ∈ ℝ ∧ +∞ ∈ ℝ) ∧ -∞ <ℝ +∞) ∨ (-∞ = -∞ ∧ +∞ = +∞))) | |
4 | 1, 2, 3 | mp2an 423 | . . 3 ⊢ (((-∞ ∈ ℝ ∧ +∞ ∈ ℝ) ∧ -∞ <ℝ +∞) ∨ (-∞ = -∞ ∧ +∞ = +∞)) |
5 | 4 | orci 721 | . 2 ⊢ ((((-∞ ∈ ℝ ∧ +∞ ∈ ℝ) ∧ -∞ <ℝ +∞) ∨ (-∞ = -∞ ∧ +∞ = +∞)) ∨ ((-∞ ∈ ℝ ∧ +∞ = +∞) ∨ (-∞ = -∞ ∧ +∞ ∈ ℝ))) |
6 | mnfxr 7846 | . . 3 ⊢ -∞ ∈ ℝ* | |
7 | pnfxr 7842 | . . 3 ⊢ +∞ ∈ ℝ* | |
8 | ltxr 9592 | . . 3 ⊢ ((-∞ ∈ ℝ* ∧ +∞ ∈ ℝ*) → (-∞ < +∞ ↔ ((((-∞ ∈ ℝ ∧ +∞ ∈ ℝ) ∧ -∞ <ℝ +∞) ∨ (-∞ = -∞ ∧ +∞ = +∞)) ∨ ((-∞ ∈ ℝ ∧ +∞ = +∞) ∨ (-∞ = -∞ ∧ +∞ ∈ ℝ))))) | |
9 | 6, 7, 8 | mp2an 423 | . 2 ⊢ (-∞ < +∞ ↔ ((((-∞ ∈ ℝ ∧ +∞ ∈ ℝ) ∧ -∞ <ℝ +∞) ∨ (-∞ = -∞ ∧ +∞ = +∞)) ∨ ((-∞ ∈ ℝ ∧ +∞ = +∞) ∨ (-∞ = -∞ ∧ +∞ ∈ ℝ)))) |
10 | 5, 9 | mpbir 145 | 1 ⊢ -∞ < +∞ |
Colors of variables: wff set class |
Syntax hints: ∧ wa 103 ↔ wb 104 ∨ wo 698 = wceq 1332 ∈ wcel 1481 class class class wbr 3937 ℝcr 7643 <ℝ cltrr 7648 +∞cpnf 7821 -∞cmnf 7822 ℝ*cxr 7823 < clt 7824 |
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-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-13 1492 ax-14 1493 ax-17 1507 ax-i9 1511 ax-ial 1515 ax-i5r 1516 ax-ext 2122 ax-sep 4054 ax-pow 4106 ax-pr 4139 ax-un 4363 ax-cnex 7735 |
This theorem depends on definitions: df-bi 116 df-3an 965 df-tru 1335 df-nf 1438 df-sb 1737 df-eu 2003 df-mo 2004 df-clab 2127 df-cleq 2133 df-clel 2136 df-nfc 2271 df-ral 2422 df-rex 2423 df-v 2691 df-un 3080 df-in 3082 df-ss 3089 df-pw 3517 df-sn 3538 df-pr 3539 df-op 3541 df-uni 3745 df-br 3938 df-opab 3998 df-xp 4553 df-pnf 7826 df-mnf 7827 df-xr 7828 df-ltxr 7829 |
This theorem is referenced by: mnfltxr 9602 xrlttr 9611 xrltso 9612 xrlttri3 9613 nltpnft 9627 npnflt 9628 ngtmnft 9630 nmnfgt 9631 xltnegi 9648 xposdif 9695 |
Copyright terms: Public domain | W3C validator |