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| Mirrors > Home > ILE Home > Th. List > negne0bi | GIF version | ||
| Description: A number is nonzero iff its negative is nonzero. (Contributed by NM, 10-Aug-1999.) | 
| Ref | Expression | 
|---|---|
| negidi.1 | ⊢ 𝐴 ∈ ℂ | 
| Ref | Expression | 
|---|---|
| negne0bi | ⊢ (𝐴 ≠ 0 ↔ -𝐴 ≠ 0) | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | negidi.1 | . . 3 ⊢ 𝐴 ∈ ℂ | |
| 2 | negeq0 8280 | . . 3 ⊢ (𝐴 ∈ ℂ → (𝐴 = 0 ↔ -𝐴 = 0)) | |
| 3 | 1, 2 | ax-mp 5 | . 2 ⊢ (𝐴 = 0 ↔ -𝐴 = 0) | 
| 4 | 3 | necon3bii 2405 | 1 ⊢ (𝐴 ≠ 0 ↔ -𝐴 ≠ 0) | 
| Colors of variables: wff set class | 
| Syntax hints: ↔ wb 105 = wceq 1364 ∈ wcel 2167 ≠ wne 2367 ℂcc 7877 0cc0 7879 -cneg 8198 | 
| 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-14 2170 ax-ext 2178 ax-sep 4151 ax-pow 4207 ax-pr 4242 ax-setind 4573 ax-resscn 7971 ax-1cn 7972 ax-icn 7974 ax-addcl 7975 ax-addrcl 7976 ax-mulcl 7977 ax-addcom 7979 ax-addass 7981 ax-distr 7983 ax-i2m1 7984 ax-0id 7987 ax-rnegex 7988 ax-cnre 7990 | 
| 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-ral 2480 df-rex 2481 df-reu 2482 df-rab 2484 df-v 2765 df-sbc 2990 df-dif 3159 df-un 3161 df-in 3163 df-ss 3170 df-pw 3607 df-sn 3628 df-pr 3629 df-op 3631 df-uni 3840 df-br 4034 df-opab 4095 df-id 4328 df-xp 4669 df-rel 4670 df-cnv 4671 df-co 4672 df-dm 4673 df-iota 5219 df-fun 5260 df-fv 5266 df-riota 5877 df-ov 5925 df-oprab 5926 df-mpo 5927 df-sub 8199 df-neg 8200 | 
| This theorem is referenced by: negne0i 8301 | 
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