Description: The generalized sum of nonnegative extended reals is not minus infinity. (Contributed by Glauco Siliprandi, 11-Oct-2020)
Ref | Expression | ||
---|---|---|---|
Hypotheses | sge0nemnf.1 | |- ( ph -> A e. V ) |
|
sge0nemnf.2 | |- ( ph -> F : A --> ( 0 [,] +oo ) ) |
||
Assertion | sge0nemnf | |- ( ph -> ( sum^ ` F ) =/= -oo ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | sge0nemnf.1 | |- ( ph -> A e. V ) |
|
2 | sge0nemnf.2 | |- ( ph -> F : A --> ( 0 [,] +oo ) ) |
|
3 | 1 2 | sge0cl | |- ( ph -> ( sum^ ` F ) e. ( 0 [,] +oo ) ) |
4 | xrge0neqmnf | |- ( ( sum^ ` F ) e. ( 0 [,] +oo ) -> ( sum^ ` F ) =/= -oo ) |
|
5 | 3 4 | syl | |- ( ph -> ( sum^ ` F ) =/= -oo ) |