Metamath Proof Explorer |
< Previous
Next >
Nearby theorems |
||
Mirrors > Home > MPE Home > Th. List > sdom1 | Structured version Visualization version GIF version |
Description: A set has less than one member iff it is empty. (Contributed by Stefan O'Rear, 28-Oct-2014.) |
Ref | Expression |
---|---|
sdom1 | ⊢ (𝐴 ≺ 1o ↔ 𝐴 = ∅) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | domnsym 8645 | . . . . 5 ⊢ (1o ≼ 𝐴 → ¬ 𝐴 ≺ 1o) | |
2 | 1 | con2i 141 | . . . 4 ⊢ (𝐴 ≺ 1o → ¬ 1o ≼ 𝐴) |
3 | 0sdom1dom 8718 | . . . 4 ⊢ (∅ ≺ 𝐴 ↔ 1o ≼ 𝐴) | |
4 | 2, 3 | sylnibr 331 | . . 3 ⊢ (𝐴 ≺ 1o → ¬ ∅ ≺ 𝐴) |
5 | relsdom 8518 | . . . . 5 ⊢ Rel ≺ | |
6 | 5 | brrelex1i 5610 | . . . 4 ⊢ (𝐴 ≺ 1o → 𝐴 ∈ V) |
7 | 0sdomg 8648 | . . . . 5 ⊢ (𝐴 ∈ V → (∅ ≺ 𝐴 ↔ 𝐴 ≠ ∅)) | |
8 | 7 | necon2bbid 3061 | . . . 4 ⊢ (𝐴 ∈ V → (𝐴 = ∅ ↔ ¬ ∅ ≺ 𝐴)) |
9 | 6, 8 | syl 17 | . . 3 ⊢ (𝐴 ≺ 1o → (𝐴 = ∅ ↔ ¬ ∅ ≺ 𝐴)) |
10 | 4, 9 | mpbird 259 | . 2 ⊢ (𝐴 ≺ 1o → 𝐴 = ∅) |
11 | 1n0 8121 | . . . 4 ⊢ 1o ≠ ∅ | |
12 | 1oex 8112 | . . . . 5 ⊢ 1o ∈ V | |
13 | 12 | 0sdom 8650 | . . . 4 ⊢ (∅ ≺ 1o ↔ 1o ≠ ∅) |
14 | 11, 13 | mpbir 233 | . . 3 ⊢ ∅ ≺ 1o |
15 | breq1 5071 | . . 3 ⊢ (𝐴 = ∅ → (𝐴 ≺ 1o ↔ ∅ ≺ 1o)) | |
16 | 14, 15 | mpbiri 260 | . 2 ⊢ (𝐴 = ∅ → 𝐴 ≺ 1o) |
17 | 10, 16 | impbii 211 | 1 ⊢ (𝐴 ≺ 1o ↔ 𝐴 = ∅) |
Colors of variables: wff setvar class |
Syntax hints: ¬ wn 3 ↔ wb 208 = wceq 1537 ∈ wcel 2114 ≠ wne 3018 Vcvv 3496 ∅c0 4293 class class class wbr 5068 1oc1o 8097 ≼ cdom 8509 ≺ csdm 8510 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1796 ax-4 1810 ax-5 1911 ax-6 1970 ax-7 2015 ax-8 2116 ax-9 2124 ax-10 2145 ax-11 2161 ax-12 2177 ax-ext 2795 ax-sep 5205 ax-nul 5212 ax-pow 5268 ax-pr 5332 ax-un 7463 |
This theorem depends on definitions: df-bi 209 df-an 399 df-or 844 df-3or 1084 df-3an 1085 df-tru 1540 df-ex 1781 df-nf 1785 df-sb 2070 df-mo 2622 df-eu 2654 df-clab 2802 df-cleq 2816 df-clel 2895 df-nfc 2965 df-ne 3019 df-ral 3145 df-rex 3146 df-rab 3149 df-v 3498 df-sbc 3775 df-dif 3941 df-un 3943 df-in 3945 df-ss 3954 df-pss 3956 df-nul 4294 df-if 4470 df-pw 4543 df-sn 4570 df-pr 4572 df-tp 4574 df-op 4576 df-uni 4841 df-br 5069 df-opab 5131 df-tr 5175 df-id 5462 df-eprel 5467 df-po 5476 df-so 5477 df-fr 5516 df-we 5518 df-xp 5563 df-rel 5564 df-cnv 5565 df-co 5566 df-dm 5567 df-rn 5568 df-res 5569 df-ima 5570 df-ord 6196 df-on 6197 df-lim 6198 df-suc 6199 df-iota 6316 df-fun 6359 df-fn 6360 df-f 6361 df-f1 6362 df-fo 6363 df-f1o 6364 df-fv 6365 df-om 7583 df-1o 8104 df-er 8291 df-en 8512 df-dom 8513 df-sdom 8514 |
This theorem is referenced by: modom 8721 frgpcyg 20722 |
Copyright terms: Public domain | W3C validator |