Description: The value of a probability is a real number. (Contributed by Thierry Arnoux, 2-Feb-2017)
Ref | Expression | ||
---|---|---|---|
Hypotheses | probmeasd.1 | |- ( ph -> P e. Prob ) |
|
probvalrnd.1 | |- ( ph -> A e. dom P ) |
||
Assertion | probvalrnd | |- ( ph -> ( P ` A ) e. RR ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | probmeasd.1 | |- ( ph -> P e. Prob ) |
|
2 | probvalrnd.1 | |- ( ph -> A e. dom P ) |
|
3 | unitssre | |- ( 0 [,] 1 ) C_ RR |
|
4 | prob01 | |- ( ( P e. Prob /\ A e. dom P ) -> ( P ` A ) e. ( 0 [,] 1 ) ) |
|
5 | 1 2 4 | syl2anc | |- ( ph -> ( P ` A ) e. ( 0 [,] 1 ) ) |
6 | 3 5 | sselid | |- ( ph -> ( P ` A ) e. RR ) |