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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 4709 | . . . 4 | |
2 | fndm 5192 | . . . . 5 | |
3 | fndm 5192 | . . . . 5 | |
4 | 2, 3 | eqeqan12d 2133 | . . . 4 |
5 | 1, 4 | syl5ib 153 | . . 3 |
6 | 5 | pm4.71rd 391 | . 2 |
7 | fneq2 5182 | . . . . . 6 | |
8 | 7 | biimparc 297 | . . . . 5 |
9 | eqfnfv 5486 | . . . . 5 | |
10 | 8, 9 | sylan2 284 | . . . 4 |
11 | 10 | anassrs 397 | . . 3 |
12 | 11 | pm5.32da 447 | . 2 |
13 | 6, 12 | bitrd 187 | 1 |
Colors of variables: wff set class |
Syntax hints: wi 4 wa 103 wb 104 wceq 1316 wral 2393 cdm 4509 wfn 5088 cfv 5093 |
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-io 683 ax-5 1408 ax-7 1409 ax-gen 1410 ax-ie1 1454 ax-ie2 1455 ax-8 1467 ax-10 1468 ax-11 1469 ax-i12 1470 ax-bndl 1471 ax-4 1472 ax-14 1477 ax-17 1491 ax-i9 1495 ax-ial 1499 ax-i5r 1500 ax-ext 2099 ax-sep 4016 ax-pow 4068 ax-pr 4101 |
This theorem depends on definitions: df-bi 116 df-3an 949 df-tru 1319 df-nf 1422 df-sb 1721 df-eu 1980 df-mo 1981 df-clab 2104 df-cleq 2110 df-clel 2113 df-nfc 2247 df-ral 2398 df-rex 2399 df-v 2662 df-sbc 2883 df-csb 2976 df-un 3045 df-in 3047 df-ss 3054 df-pw 3482 df-sn 3503 df-pr 3504 df-op 3506 df-uni 3707 df-br 3900 df-opab 3960 df-mpt 3961 df-id 4185 df-xp 4515 df-rel 4516 df-cnv 4517 df-co 4518 df-dm 4519 df-iota 5058 df-fun 5095 df-fn 5096 df-fv 5101 |
This theorem is referenced by: eqfnfv3 5488 eqfunfv 5491 eqfnov 5845 2ffzeq 9886 |
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