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Mirrors > Home > ILE Home > Th. List > eqfnfv2 | Unicode version |
Description: Equality of functions is determined by their values. Exercise 4 of [TakeutiZaring] p. 28. (Contributed by NM, 3-Aug-1994.) (Revised by Mario Carneiro, 31-Aug-2015.) |
Ref | Expression |
---|---|
eqfnfv2 |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | dmeq 4535 | . . . 4 | |
2 | fndm 4998 | . . . . 5 | |
3 | fndm 4998 | . . . . 5 | |
4 | 2, 3 | eqeqan12d 2055 | . . . 4 |
5 | 1, 4 | syl5ib 143 | . . 3 |
6 | 5 | pm4.71rd 374 | . 2 |
7 | fneq2 4988 | . . . . . 6 | |
8 | 7 | biimparc 283 | . . . . 5 |
9 | eqfnfv 5265 | . . . . 5 | |
10 | 8, 9 | sylan2 270 | . . . 4 |
11 | 10 | anassrs 380 | . . 3 |
12 | 11 | pm5.32da 425 | . 2 |
13 | 6, 12 | bitrd 177 | 1 |
Colors of variables: wff set class |
Syntax hints: wi 4 wa 97 wb 98 wceq 1243 wral 2306 cdm 4345 wfn 4897 cfv 4902 |
This theorem was proved from axioms: ax-1 5 ax-2 6 ax-mp 7 ax-ia1 99 ax-ia2 100 ax-ia3 101 ax-io 630 ax-5 1336 ax-7 1337 ax-gen 1338 ax-ie1 1382 ax-ie2 1383 ax-8 1395 ax-10 1396 ax-11 1397 ax-i12 1398 ax-bndl 1399 ax-4 1400 ax-14 1405 ax-17 1419 ax-i9 1423 ax-ial 1427 ax-i5r 1428 ax-ext 2022 ax-sep 3875 ax-pow 3927 ax-pr 3944 |
This theorem depends on definitions: df-bi 110 df-3an 887 df-tru 1246 df-nf 1350 df-sb 1646 df-eu 1903 df-mo 1904 df-clab 2027 df-cleq 2033 df-clel 2036 df-nfc 2167 df-ral 2311 df-rex 2312 df-v 2559 df-sbc 2765 df-csb 2853 df-un 2922 df-in 2924 df-ss 2931 df-pw 3361 df-sn 3381 df-pr 3382 df-op 3384 df-uni 3581 df-br 3765 df-opab 3819 df-mpt 3820 df-id 4030 df-xp 4351 df-rel 4352 df-cnv 4353 df-co 4354 df-dm 4355 df-iota 4867 df-fun 4904 df-fn 4905 df-fv 4910 |
This theorem is referenced by: eqfnfv3 5267 eqfunfv 5270 eqfnov 5607 2ffzeq 8998 |
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