Description: The generalized sum of nonnegative extended reals is an extended real. (Contributed by Glauco Siliprandi, 11-Oct-2020)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | sge0xrclmpt.xph | |- F/ x ph |
|
| sge0xrclmpt.a | |- ( ph -> A e. V ) |
||
| sge0xrclmpt.b | |- ( ( ph /\ x e. A ) -> B e. ( 0 [,] +oo ) ) |
||
| Assertion | sge0xrclmpt | |- ( ph -> ( sum^ ` ( x e. A |-> B ) ) e. RR* ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | sge0xrclmpt.xph | |- F/ x ph |
|
| 2 | sge0xrclmpt.a | |- ( ph -> A e. V ) |
|
| 3 | sge0xrclmpt.b | |- ( ( ph /\ x e. A ) -> B e. ( 0 [,] +oo ) ) |
|
| 4 | iccssxr | |- ( 0 [,] +oo ) C_ RR* |
|
| 5 | 1 2 3 | sge0clmpt | |- ( ph -> ( sum^ ` ( x e. A |-> B ) ) e. ( 0 [,] +oo ) ) |
| 6 | 4 5 | sselid | |- ( ph -> ( sum^ ` ( x e. A |-> B ) ) e. RR* ) |