Theorem lt0ne0 8472

Description: A number which is less than zero is not zero. See also lt0ap0 8692 which is similar but for apartness. (Contributed by Stefan O'Rear, 13-Sep-2014.)

Assertion

Ref	Expression
lt0ne0	|- ( ( A e. RR /\ A < 0 ) -> A =/= 0 )

Proof of Theorem lt0ne0

Step	Hyp	Ref	Expression
1		ltne 8128	. 2 |- ( ( A e. RR /\ A < 0 ) -> 0 =/= A )
2	1	necomd 2453	1 |- ( ( A e. RR /\ A < 0 ) -> A =/= 0 )

Syntax hints:   -> wi 4   /\ wa 104   e. wcel 2167   =/= wne 2367   class class class wbr 4034   RRcr 7895   0cc0 7896   < clt 8078

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 615  ax-in2 616  ax-io 710  ax-5 1461  ax-7 1462  ax-gen 1463  ax-ie1 1507  ax-ie2 1508  ax-8 1518  ax-10 1519  ax-11 1520  ax-i12 1521  ax-bndl 1523  ax-4 1524  ax-17 1540  ax-i9 1544  ax-ial 1548  ax-i5r 1549  ax-13 2169  ax-14 2170  ax-ext 2178  ax-sep 4152  ax-pow 4208  ax-pr 4243  ax-un 4469  ax-setind 4574  ax-cnex 7987  ax-resscn 7988  ax-pre-ltirr 8008

This theorem depends on definitions:  df-bi 117  df-3an 982  df-tru 1367  df-fal 1370  df-nf 1475  df-sb 1777  df-eu 2048  df-mo 2049  df-clab 2183  df-cleq 2189  df-clel 2192  df-nfc 2328  df-ne 2368  df-nel 2463  df-ral 2480  df-rex 2481  df-rab 2484  df-v 2765  df-dif 3159  df-un 3161  df-in 3163  df-ss 3170  df-pw 3608  df-sn 3629  df-pr 3630  df-op 3632  df-uni 3841  df-br 4035  df-opab 4096  df-xp 4670  df-pnf 8080  df-mnf 8081  df-ltxr 8083

This theorem is referenced by: (None)