![]() |
Metamath Proof Explorer |
< Previous
Next >
Nearby theorems |
|
Mirrors > Home > MPE Home > Th. List > sbievw2 | Structured version Visualization version GIF version |
Description: sbievw 2100 applied twice, avoiding a DV condition on 𝑥, 𝑦. Based on proofs by Wolf Lammen. (Contributed by Steven Nguyen, 29-Jul-2023.) |
Ref | Expression |
---|---|
sbievw2.1 | ⊢ (𝑥 = 𝑤 → (𝜑 ↔ 𝜒)) |
sbievw2.2 | ⊢ (𝑤 = 𝑦 → (𝜒 ↔ 𝜓)) |
Ref | Expression |
---|---|
sbievw2 | ⊢ ([𝑦 / 𝑥]𝜑 ↔ 𝜓) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | sbcom3vv 2103 | . . 3 ⊢ ([𝑦 / 𝑤][𝑤 / 𝑥]𝜑 ↔ [𝑦 / 𝑤][𝑦 / 𝑥]𝜑) | |
2 | sbievw2.1 | . . . . 5 ⊢ (𝑥 = 𝑤 → (𝜑 ↔ 𝜒)) | |
3 | 2 | sbievw 2100 | . . . 4 ⊢ ([𝑤 / 𝑥]𝜑 ↔ 𝜒) |
4 | 3 | sbbii 2081 | . . 3 ⊢ ([𝑦 / 𝑤][𝑤 / 𝑥]𝜑 ↔ [𝑦 / 𝑤]𝜒) |
5 | sbv 2095 | . . 3 ⊢ ([𝑦 / 𝑤][𝑦 / 𝑥]𝜑 ↔ [𝑦 / 𝑥]𝜑) | |
6 | 1, 4, 5 | 3bitr3i 304 | . 2 ⊢ ([𝑦 / 𝑤]𝜒 ↔ [𝑦 / 𝑥]𝜑) |
7 | sbievw2.2 | . . 3 ⊢ (𝑤 = 𝑦 → (𝜒 ↔ 𝜓)) | |
8 | 7 | sbievw 2100 | . 2 ⊢ ([𝑦 / 𝑤]𝜒 ↔ 𝜓) |
9 | 6, 8 | bitr3i 280 | 1 ⊢ ([𝑦 / 𝑥]𝜑 ↔ 𝜓) |
Colors of variables: wff setvar class |
Syntax hints: → wi 4 ↔ wb 209 [wsb 2069 |
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 |
This theorem depends on definitions: df-bi 210 df-an 400 df-ex 1782 df-sb 2070 |
This theorem is referenced by: sbco2vv 2105 equsb3 2106 equsb3r 2107 elsb3 2119 elsb4 2127 eqsb3 2916 clelsb3 2917 sbss 4420 |
Copyright terms: Public domain | W3C validator |