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Mirrors > Home > ILE Home > Th. List > sbcom | Unicode version |
Description: A commutativity law for substitution. (Contributed by NM, 27-May-1997.) (Proof rewritten by Jim Kingdon, 22-Mar-2018.) |
Ref | Expression |
---|---|
sbcom |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | sbco3 1889 | . 2 | |
2 | sbcocom 1885 | . 2 | |
3 | sbcocom 1885 | . 2 | |
4 | 1, 2, 3 | 3bitr3i 208 | 1 |
Colors of variables: wff set class |
Syntax hints: wb 103 wsb 1685 |
This theorem was proved from axioms: ax-1 5 ax-2 6 ax-mp 7 ax-ia1 104 ax-ia2 105 ax-ia3 106 ax-io 662 ax-5 1376 ax-7 1377 ax-gen 1378 ax-ie1 1422 ax-ie2 1423 ax-8 1435 ax-10 1436 ax-11 1437 ax-i12 1438 ax-bndl 1439 ax-4 1440 ax-17 1459 ax-i9 1463 ax-ial 1467 ax-i5r 1468 |
This theorem depends on definitions: df-bi 115 df-nf 1390 df-sb 1686 |
This theorem is referenced by: sb9 1896 |
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