Description: The Borel Algebra is a set of subsets of the real numbers. (Contributed by Thierry Arnoux, 19-Jan-2017)
Ref | Expression | ||
---|---|---|---|
Assertion | brsigasspwrn | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | brsigarn | |
|
2 | sigasspw | |
|
3 | 1 2 | ax-mp | |