Intuitionistic Logic Explorer |
< Previous
Next >
Nearby theorems |
||
Mirrors > Home > ILE Home > Th. List > renepnf | GIF version |
Description: No (finite) real equals plus infinity. (Contributed by NM, 14-Oct-2005.) (Proof shortened by Andrew Salmon, 19-Nov-2011.) |
Ref | Expression |
---|---|
renepnf | ⊢ (𝐴 ∈ ℝ → 𝐴 ≠ +∞) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | pnfnre 7800 | . . . 4 ⊢ +∞ ∉ ℝ | |
2 | 1 | neli 2403 | . . 3 ⊢ ¬ +∞ ∈ ℝ |
3 | eleq1 2200 | . . 3 ⊢ (𝐴 = +∞ → (𝐴 ∈ ℝ ↔ +∞ ∈ ℝ)) | |
4 | 2, 3 | mtbiri 664 | . 2 ⊢ (𝐴 = +∞ → ¬ 𝐴 ∈ ℝ) |
5 | 4 | necon2ai 2360 | 1 ⊢ (𝐴 ∈ ℝ → 𝐴 ≠ +∞) |
Colors of variables: wff set class |
Syntax hints: → wi 4 = wceq 1331 ∈ wcel 1480 ≠ wne 2306 ℝcr 7612 +∞cpnf 7790 |
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 603 ax-in2 604 ax-io 698 ax-5 1423 ax-7 1424 ax-gen 1425 ax-ie1 1469 ax-ie2 1470 ax-8 1482 ax-10 1483 ax-11 1484 ax-i12 1485 ax-bndl 1486 ax-4 1487 ax-13 1491 ax-14 1492 ax-17 1506 ax-i9 1510 ax-ial 1514 ax-i5r 1515 ax-ext 2119 ax-sep 4041 ax-un 4350 ax-cnex 7704 ax-resscn 7705 |
This theorem depends on definitions: df-bi 116 df-tru 1334 df-fal 1337 df-nf 1437 df-sb 1736 df-clab 2124 df-cleq 2130 df-clel 2133 df-nfc 2268 df-ne 2307 df-nel 2402 df-rex 2420 df-rab 2423 df-v 2683 df-in 3072 df-ss 3079 df-pw 3507 df-uni 3732 df-pnf 7795 |
This theorem is referenced by: renepnfd 7809 renfdisj 7817 ltxrlt 7823 xrnepnf 9558 xrlttri3 9576 nltpnft 9590 xrrebnd 9595 rexneg 9606 xrpnfdc 9618 rexadd 9628 xaddnepnf 9634 xaddcom 9637 xaddid1 9638 xnn0xadd0 9643 xnegdi 9644 xpncan 9647 xleadd1a 9649 xltadd1 9652 xsubge0 9657 xposdif 9658 xleaddadd 9663 xrmaxrecl 11017 |
Copyright terms: Public domain | W3C validator |