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Mirrors > Home > ILE Home > Th. List > eqeq2 | GIF version |
Description: Equality implies equivalence of equalities. (Contributed by NM, 5-Aug-1993.) |
Ref | Expression |
---|---|
eqeq2 | ⊢ (𝐴 = 𝐵 → (𝐶 = 𝐴 ↔ 𝐶 = 𝐵)) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | eqeq1 2087 | . 2 ⊢ (𝐴 = 𝐵 → (𝐴 = 𝐶 ↔ 𝐵 = 𝐶)) | |
2 | eqcom 2083 | . 2 ⊢ (𝐶 = 𝐴 ↔ 𝐴 = 𝐶) | |
3 | eqcom 2083 | . 2 ⊢ (𝐶 = 𝐵 ↔ 𝐵 = 𝐶) | |
4 | 1, 2, 3 | 3bitr4g 221 | 1 ⊢ (𝐴 = 𝐵 → (𝐶 = 𝐴 ↔ 𝐶 = 𝐵)) |
Colors of variables: wff set class |
Syntax hints: → wi 4 ↔ wb 103 = wceq 1284 |
This theorem was proved from axioms: ax-1 5 ax-2 6 ax-mp 7 ax-ia1 104 ax-ia2 105 ax-ia3 106 ax-5 1376 ax-gen 1378 ax-4 1440 ax-17 1459 ax-ext 2063 |
This theorem depends on definitions: df-bi 115 df-cleq 2074 |
This theorem is referenced by: eqeq2i 2091 eqeq2d 2092 eqeq12 2093 eleq1 2141 neeq2 2259 alexeq 2721 ceqex 2722 pm13.183 2732 eqeu 2762 mo2icl 2771 mob2 2772 euind 2779 reu6i 2783 reuind 2795 sbc5 2838 csbiebg 2945 sneq 3409 preqr1g 3558 preqr1 3560 prel12 3563 preq12bg 3565 opth 3992 euotd 4009 ordtriexmid 4265 wetriext 4319 tfisi 4328 ideqg 4505 resieq 4640 cnveqb 4796 cnveq0 4797 iota5 4907 funopg 4954 fneq2 5008 foeq3 5124 tz6.12f 5223 funbrfv 5233 fnbrfvb 5235 fvelimab 5250 elrnrexdm 5327 eufnfv 5410 f1veqaeq 5429 mpt2eq123 5584 ovmpt4g 5643 ovi3 5657 ovg 5659 caovcang 5682 caovcan 5685 nntri3or 6095 nnaordex 6123 nnawordex 6124 ereq2 6137 eroveu 6220 2dom 6308 fundmen 6309 nneneq 6343 supsnti 6418 isotilem 6419 nqtri3or 6586 ltexnqq 6598 aptisr 6955 srpospr 6959 axpre-apti 7051 nntopi 7060 subval 7300 divvalap 7762 nn0ind-raph 8464 frecuzrdgfn 9414 sqrtrval 9886 divides 10197 dvdstr 10232 odd2np1lem 10271 ndvdssub 10330 eucalglt 10439 |
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