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| Mirrors > Home > MPE Home > Th. List > symgextfv | Structured version Visualization version GIF version | ||
| Description: The function value of the extension of a permutation, fixing the additional element, for elements in the original domain. (Contributed by AV, 6-Jan-2019.) |
| Ref | Expression |
|---|---|
| symgext.s | ⊢ 𝑆 = (Base‘(SymGrp‘(𝑁 ∖ {𝐾}))) |
| symgext.e | ⊢ 𝐸 = (𝑥 ∈ 𝑁 ↦ if(𝑥 = 𝐾, 𝐾, (𝑍‘𝑥))) |
| Ref | Expression |
|---|---|
| symgextfv | ⊢ ((𝐾 ∈ 𝑁 ∧ 𝑍 ∈ 𝑆) → (𝑋 ∈ (𝑁 ∖ {𝐾}) → (𝐸‘𝑋) = (𝑍‘𝑋))) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | eldifi 4084 | . . . 4 ⊢ (𝑋 ∈ (𝑁 ∖ {𝐾}) → 𝑋 ∈ 𝑁) | |
| 2 | fvexd 6882 | . . . . 5 ⊢ ((𝐾 ∈ 𝑁 ∧ 𝑍 ∈ 𝑆) → (𝑍‘𝑋) ∈ V) | |
| 3 | ifexg 4530 | . . . . 5 ⊢ ((𝐾 ∈ 𝑁 ∧ (𝑍‘𝑋) ∈ V) → if(𝑋 = 𝐾, 𝐾, (𝑍‘𝑋)) ∈ V) | |
| 4 | 2, 3 | syldan 600 | . . . 4 ⊢ ((𝐾 ∈ 𝑁 ∧ 𝑍 ∈ 𝑆) → if(𝑋 = 𝐾, 𝐾, (𝑍‘𝑋)) ∈ V) |
| 5 | eqeq1 2766 | . . . . . 6 ⊢ (𝑥 = 𝑋 → (𝑥 = 𝐾 ↔ 𝑋 = 𝐾)) | |
| 6 | fveq2 6867 | . . . . . 6 ⊢ (𝑥 = 𝑋 → (𝑍‘𝑥) = (𝑍‘𝑋)) | |
| 7 | 5, 6 | ifbieq2d 4507 | . . . . 5 ⊢ (𝑥 = 𝑋 → if(𝑥 = 𝐾, 𝐾, (𝑍‘𝑥)) = if(𝑋 = 𝐾, 𝐾, (𝑍‘𝑋))) |
| 8 | symgext.e | . . . . 5 ⊢ 𝐸 = (𝑥 ∈ 𝑁 ↦ if(𝑥 = 𝐾, 𝐾, (𝑍‘𝑥))) | |
| 9 | 7, 8 | fvmptg 6973 | . . . 4 ⊢ ((𝑋 ∈ 𝑁 ∧ if(𝑋 = 𝐾, 𝐾, (𝑍‘𝑋)) ∈ V) → (𝐸‘𝑋) = if(𝑋 = 𝐾, 𝐾, (𝑍‘𝑋))) |
| 10 | 1, 4, 9 | syl2anr 606 | . . 3 ⊢ (((𝐾 ∈ 𝑁 ∧ 𝑍 ∈ 𝑆) ∧ 𝑋 ∈ (𝑁 ∖ {𝐾})) → (𝐸‘𝑋) = if(𝑋 = 𝐾, 𝐾, (𝑍‘𝑋))) |
| 11 | eldifsnneq 4751 | . . . . 5 ⊢ (𝑋 ∈ (𝑁 ∖ {𝐾}) → ¬ 𝑋 = 𝐾) | |
| 12 | 11 | adantl 485 | . . . 4 ⊢ (((𝐾 ∈ 𝑁 ∧ 𝑍 ∈ 𝑆) ∧ 𝑋 ∈ (𝑁 ∖ {𝐾})) → ¬ 𝑋 = 𝐾) |
| 13 | 12 | iffalsed 4491 | . . 3 ⊢ (((𝐾 ∈ 𝑁 ∧ 𝑍 ∈ 𝑆) ∧ 𝑋 ∈ (𝑁 ∖ {𝐾})) → if(𝑋 = 𝐾, 𝐾, (𝑍‘𝑋)) = (𝑍‘𝑋)) |
| 14 | 10, 13 | eqtrd 2797 | . 2 ⊢ (((𝐾 ∈ 𝑁 ∧ 𝑍 ∈ 𝑆) ∧ 𝑋 ∈ (𝑁 ∖ {𝐾})) → (𝐸‘𝑋) = (𝑍‘𝑋)) |
| 15 | 14 | ex 416 | 1 ⊢ ((𝐾 ∈ 𝑁 ∧ 𝑍 ∈ 𝑆) → (𝑋 ∈ (𝑁 ∖ {𝐾}) → (𝐸‘𝑋) = (𝑍‘𝑋))) |
| Colors of variables: wff setvar class |
| Syntax hints: ¬ wn 3 → wi 4 ∧ wa 399 = wceq 1560 ∈ wcel 2142 Vcvv 3454 ∖ cdif 3901 ifcif 4480 {csn 4582 ↦ cmpt 5181 ‘cfv 6521 Basecbs 17245 SymGrpcsymg 19409 |
| This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1815 ax-4 1829 ax-5 1930 ax-6 1987 ax-7 2028 ax-8 2144 ax-9 2152 ax-10 2175 ax-11 2191 ax-12 2212 ax-ext 2734 ax-sep 5246 ax-nul 5256 ax-pr 5390 |
| This theorem depends on definitions: df-bi 209 df-an 400 df-or 859 df-3an 1100 df-tru 1563 df-fal 1573 df-ex 1800 df-nf 1804 df-sb 2091 df-mo 2566 df-eu 2596 df-clab 2741 df-cleq 2754 df-clel 2837 df-nfc 2911 df-ne 2958 df-ral 3077 df-rex 3087 df-rab 3415 df-v 3456 df-dif 3907 df-un 3909 df-in 3911 df-ss 3921 df-nul 4286 df-if 4481 df-sn 4583 df-pr 4585 df-op 4589 df-uni 4866 df-br 5101 df-opab 5163 df-mpt 5182 df-id 5542 df-xp 5653 df-rel 5654 df-cnv 5655 df-co 5656 df-dm 5657 df-iota 6477 df-fun 6523 df-fv 6529 |
| This theorem is referenced by: symgextf1lem 19460 symgextf1 19461 symgextfo 19462 symgextres 19465 |
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