Description: A function restricted to upper integers converges iff the original function converges. (Contributed by Glauco Siliprandi, 23-Apr-2023)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | climresd.1 | |- ( ph -> M e. ZZ ) | |
| climresd.2 | |- ( ph -> F e. V ) | ||
| Assertion | climresd | |- ( ph -> ( ( F |` ( ZZ>= ` M ) ) ~~> A <-> F ~~> A ) ) | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | climresd.1 | |- ( ph -> M e. ZZ ) | |
| 2 | climresd.2 | |- ( ph -> F e. V ) | |
| 3 | climres | |- ( ( M e. ZZ /\ F e. V ) -> ( ( F |` ( ZZ>= ` M ) ) ~~> A <-> F ~~> A ) ) | |
| 4 | 1 2 3 | syl2anc | |- ( ph -> ( ( F |` ( ZZ>= ` M ) ) ~~> A <-> F ~~> A ) ) |