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Mirrors > Home > ILE Home > Th. List > f0dom0 | Unicode version |
Description: A function is empty iff it has an empty domain. (Contributed by AV, 10-Feb-2019.) |
Ref | Expression |
---|---|
f0dom0 |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | feq2 5264 | . . . 4 | |
2 | f0bi 5323 | . . . . 5 | |
3 | 2 | biimpi 119 | . . . 4 |
4 | 1, 3 | syl6bi 162 | . . 3 |
5 | 4 | com12 30 | . 2 |
6 | feq1 5263 | . . . 4 | |
7 | dm0 4761 | . . . . 5 | |
8 | fdm 5286 | . . . . 5 | |
9 | 7, 8 | syl5reqr 2188 | . . . 4 |
10 | 6, 9 | syl6bi 162 | . . 3 |
11 | 10 | com12 30 | . 2 |
12 | 5, 11 | impbid 128 | 1 |
Colors of variables: wff set class |
Syntax hints: wi 4 wb 104 wceq 1332 c0 3368 cdm 4547 wf 5127 |
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 604 ax-in2 605 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-14 1493 ax-17 1507 ax-i9 1511 ax-ial 1515 ax-i5r 1516 ax-ext 2122 ax-sep 4054 ax-nul 4062 ax-pow 4106 ax-pr 4139 |
This theorem depends on definitions: df-bi 116 df-3an 965 df-tru 1335 df-fal 1338 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-dif 3078 df-un 3080 df-in 3082 df-ss 3089 df-nul 3369 df-pw 3517 df-sn 3538 df-pr 3539 df-op 3541 df-br 3938 df-opab 3998 df-id 4223 df-xp 4553 df-rel 4554 df-cnv 4555 df-co 4556 df-dm 4557 df-rn 4558 df-fun 5133 df-fn 5134 df-f 5135 |
This theorem is referenced by: (None) |
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