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Mirrors > Home > ILE Home > Th. List > sbco3xzyz | GIF version |
Description: Version of sbco3 1972 with distinct variable constraints between 𝑥 and 𝑧, and 𝑦 and 𝑧. Lemma for proving sbco3 1972. (Contributed by Jim Kingdon, 22-Mar-2018.) |
Ref | Expression |
---|---|
sbco3xzyz | ⊢ ([𝑧 / 𝑦][𝑦 / 𝑥]𝜑 ↔ [𝑧 / 𝑥][𝑥 / 𝑦]𝜑) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | sbcomxyyz 1970 | . 2 ⊢ ([𝑧 / 𝑦][𝑧 / 𝑥]𝜑 ↔ [𝑧 / 𝑥][𝑧 / 𝑦]𝜑) | |
2 | sbcocom 1968 | . 2 ⊢ ([𝑧 / 𝑦][𝑦 / 𝑥]𝜑 ↔ [𝑧 / 𝑦][𝑧 / 𝑥]𝜑) | |
3 | sbcocom 1968 | . 2 ⊢ ([𝑧 / 𝑥][𝑥 / 𝑦]𝜑 ↔ [𝑧 / 𝑥][𝑧 / 𝑦]𝜑) | |
4 | 1, 2, 3 | 3bitr4i 212 | 1 ⊢ ([𝑧 / 𝑦][𝑦 / 𝑥]𝜑 ↔ [𝑧 / 𝑥][𝑥 / 𝑦]𝜑) |
Colors of variables: wff set class |
Syntax hints: ↔ wb 105 [wsb 1760 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-ia1 106 ax-ia2 107 ax-ia3 108 ax-io 709 ax-5 1445 ax-7 1446 ax-gen 1447 ax-ie1 1491 ax-ie2 1492 ax-8 1502 ax-10 1503 ax-11 1504 ax-i12 1505 ax-bndl 1507 ax-4 1508 ax-17 1524 ax-i9 1528 ax-ial 1532 ax-i5r 1533 |
This theorem depends on definitions: df-bi 117 df-nf 1459 df-sb 1761 |
This theorem is referenced by: sbco3 1972 |
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