Description: A singleton is measurable. (Contributed by Glauco Siliprandi, 11-Dec-2019)
Ref | Expression | ||
---|---|---|---|
Assertion | snmbl | |- ( A e. RR -> { A } e. dom vol ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | snssi | |- ( A e. RR -> { A } C_ RR ) |
|
2 | ovolsn | |- ( A e. RR -> ( vol* ` { A } ) = 0 ) |
|
3 | nulmbl | |- ( ( { A } C_ RR /\ ( vol* ` { A } ) = 0 ) -> { A } e. dom vol ) |
|
4 | 1 2 3 | syl2anc | |- ( A e. RR -> { A } e. dom vol ) |