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 ) |