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Mathbox for Giovanni Mascellani |
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Mirrors > Home > MPE Home > Th. List > Mathboxes > sbccom2f | Structured version Visualization version GIF version |
Description: Commutative law for double class substitution, with nonfree variable condition. (Contributed by Giovanni Mascellani, 31-May-2019.) |
Ref | Expression |
---|---|
sbccom2f.1 | ⊢ 𝐴 ∈ V |
sbccom2f.2 | ⊢ Ⅎ𝑦𝐴 |
Ref | Expression |
---|---|
sbccom2f | ⊢ ([𝐴 / 𝑥][𝐵 / 𝑦]𝜑 ↔ [⦋𝐴 / 𝑥⦌𝐵 / 𝑦][𝐴 / 𝑥]𝜑) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | sbcco 3746 | . . . 4 ⊢ ([𝐵 / 𝑧][𝑧 / 𝑦]𝜑 ↔ [𝐵 / 𝑦]𝜑) | |
2 | 1 | bicomi 227 | . . 3 ⊢ ([𝐵 / 𝑦]𝜑 ↔ [𝐵 / 𝑧][𝑧 / 𝑦]𝜑) |
3 | 2 | sbcbii 3776 | . 2 ⊢ ([𝐴 / 𝑥][𝐵 / 𝑦]𝜑 ↔ [𝐴 / 𝑥][𝐵 / 𝑧][𝑧 / 𝑦]𝜑) |
4 | sbccom2f.1 | . . 3 ⊢ 𝐴 ∈ V | |
5 | 4 | sbccom2 35563 | . 2 ⊢ ([𝐴 / 𝑥][𝐵 / 𝑧][𝑧 / 𝑦]𝜑 ↔ [⦋𝐴 / 𝑥⦌𝐵 / 𝑧][𝐴 / 𝑥][𝑧 / 𝑦]𝜑) |
6 | vex 3444 | . . . . . . 7 ⊢ 𝑧 ∈ V | |
7 | 6 | sbccom2 35563 | . . . . . 6 ⊢ ([𝑧 / 𝑦][𝐴 / 𝑥]𝜑 ↔ [⦋𝑧 / 𝑦⦌𝐴 / 𝑥][𝑧 / 𝑦]𝜑) |
8 | sbccom2f.2 | . . . . . . . 8 ⊢ Ⅎ𝑦𝐴 | |
9 | 6, 8 | csbgfi 3848 | . . . . . . 7 ⊢ ⦋𝑧 / 𝑦⦌𝐴 = 𝐴 |
10 | dfsbcq 3722 | . . . . . . 7 ⊢ (⦋𝑧 / 𝑦⦌𝐴 = 𝐴 → ([⦋𝑧 / 𝑦⦌𝐴 / 𝑥][𝑧 / 𝑦]𝜑 ↔ [𝐴 / 𝑥][𝑧 / 𝑦]𝜑)) | |
11 | 9, 10 | ax-mp 5 | . . . . . 6 ⊢ ([⦋𝑧 / 𝑦⦌𝐴 / 𝑥][𝑧 / 𝑦]𝜑 ↔ [𝐴 / 𝑥][𝑧 / 𝑦]𝜑) |
12 | 7, 11 | bitri 278 | . . . . 5 ⊢ ([𝑧 / 𝑦][𝐴 / 𝑥]𝜑 ↔ [𝐴 / 𝑥][𝑧 / 𝑦]𝜑) |
13 | 12 | bicomi 227 | . . . 4 ⊢ ([𝐴 / 𝑥][𝑧 / 𝑦]𝜑 ↔ [𝑧 / 𝑦][𝐴 / 𝑥]𝜑) |
14 | 13 | sbcbii 3776 | . . 3 ⊢ ([⦋𝐴 / 𝑥⦌𝐵 / 𝑧][𝐴 / 𝑥][𝑧 / 𝑦]𝜑 ↔ [⦋𝐴 / 𝑥⦌𝐵 / 𝑧][𝑧 / 𝑦][𝐴 / 𝑥]𝜑) |
15 | sbcco 3746 | . . 3 ⊢ ([⦋𝐴 / 𝑥⦌𝐵 / 𝑧][𝑧 / 𝑦][𝐴 / 𝑥]𝜑 ↔ [⦋𝐴 / 𝑥⦌𝐵 / 𝑦][𝐴 / 𝑥]𝜑) | |
16 | 14, 15 | bitri 278 | . 2 ⊢ ([⦋𝐴 / 𝑥⦌𝐵 / 𝑧][𝐴 / 𝑥][𝑧 / 𝑦]𝜑 ↔ [⦋𝐴 / 𝑥⦌𝐵 / 𝑦][𝐴 / 𝑥]𝜑) |
17 | 3, 5, 16 | 3bitri 300 | 1 ⊢ ([𝐴 / 𝑥][𝐵 / 𝑦]𝜑 ↔ [⦋𝐴 / 𝑥⦌𝐵 / 𝑦][𝐴 / 𝑥]𝜑) |
Colors of variables: wff setvar class |
Syntax hints: ↔ wb 209 = wceq 1538 ∈ wcel 2111 Ⅎwnfc 2936 Vcvv 3441 [wsbc 3720 ⦋csb 3828 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1797 ax-4 1811 ax-5 1911 ax-6 1970 ax-7 2015 ax-8 2113 ax-9 2121 ax-10 2142 ax-11 2158 ax-12 2175 ax-13 2379 ax-ext 2770 |
This theorem depends on definitions: df-bi 210 df-an 400 df-or 845 df-tru 1541 df-ex 1782 df-nf 1786 df-sb 2070 df-clab 2777 df-cleq 2791 df-clel 2870 df-nfc 2938 df-v 3443 df-sbc 3721 df-csb 3829 |
This theorem is referenced by: sbccom2fi 35565 |
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