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| Mirrors > Home > MPE Home > Th. List > Mathboxes > cdleme31sdnN | Structured version Visualization version GIF version | ||
| Description: Part of proof of Lemma E in [Crawley] p. 113. (Contributed by NM, 31-Mar-2013.) (New usage is discouraged.) |
| Ref | Expression |
|---|---|
| cdleme31sdn.c | ⊢ 𝐶 = ((𝑠 ∨ 𝑈) ∧ (𝑄 ∨ ((𝑃 ∨ 𝑠) ∧ 𝑊))) |
| cdleme31sdn.d | ⊢ 𝐷 = ((𝑡 ∨ 𝑈) ∧ (𝑄 ∨ ((𝑃 ∨ 𝑡) ∧ 𝑊))) |
| cdleme31sdn.n | ⊢ 𝑁 = if(𝑠 ≤ (𝑃 ∨ 𝑄), 𝐼, 𝐶) |
| Ref | Expression |
|---|---|
| cdleme31sdnN | ⊢ 𝑁 = if(𝑠 ≤ (𝑃 ∨ 𝑄), 𝐼, ⦋𝑠 / 𝑡⦌𝐷) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | cdleme31sdn.n | . 2 ⊢ 𝑁 = if(𝑠 ≤ (𝑃 ∨ 𝑄), 𝐼, 𝐶) | |
| 2 | biid 261 | . . 3 ⊢ (𝑠 ≤ (𝑃 ∨ 𝑄) ↔ 𝑠 ≤ (𝑃 ∨ 𝑄)) | |
| 3 | cdleme31sdn.d | . . . . 5 ⊢ 𝐷 = ((𝑡 ∨ 𝑈) ∧ (𝑄 ∨ ((𝑃 ∨ 𝑡) ∧ 𝑊))) | |
| 4 | cdleme31sdn.c | . . . . 5 ⊢ 𝐶 = ((𝑠 ∨ 𝑈) ∧ (𝑄 ∨ ((𝑃 ∨ 𝑠) ∧ 𝑊))) | |
| 5 | 3, 4 | cdleme31sc 40386 | . . . 4 ⊢ (𝑠 ∈ V → ⦋𝑠 / 𝑡⦌𝐷 = 𝐶) |
| 6 | 5 | elv 3485 | . . 3 ⊢ ⦋𝑠 / 𝑡⦌𝐷 = 𝐶 |
| 7 | 2, 6 | ifbieq2i 4551 | . 2 ⊢ if(𝑠 ≤ (𝑃 ∨ 𝑄), 𝐼, ⦋𝑠 / 𝑡⦌𝐷) = if(𝑠 ≤ (𝑃 ∨ 𝑄), 𝐼, 𝐶) |
| 8 | 1, 7 | eqtr4i 2768 | 1 ⊢ 𝑁 = if(𝑠 ≤ (𝑃 ∨ 𝑄), 𝐼, ⦋𝑠 / 𝑡⦌𝐷) |
| Colors of variables: wff setvar class |
| Syntax hints: = wceq 1540 Vcvv 3480 ⦋csb 3899 ifcif 4525 class class class wbr 5143 (class class class)co 7431 |
| This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1795 ax-4 1809 ax-5 1910 ax-6 1967 ax-7 2007 ax-8 2110 ax-9 2118 ax-10 2141 ax-11 2157 ax-12 2177 ax-ext 2708 |
| This theorem depends on definitions: df-bi 207 df-an 396 df-or 849 df-3an 1089 df-tru 1543 df-fal 1553 df-ex 1780 df-nf 1784 df-sb 2065 df-clab 2715 df-cleq 2729 df-clel 2816 df-nfc 2892 df-rab 3437 df-v 3482 df-sbc 3789 df-csb 3900 df-dif 3954 df-un 3956 df-ss 3968 df-nul 4334 df-if 4526 df-sn 4627 df-pr 4629 df-op 4633 df-uni 4908 df-br 5144 df-iota 6514 df-fv 6569 df-ov 7434 |
| This theorem is referenced by: (None) |
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