Metamath Proof Explorer


Theorem climcl

Description: Closure of the limit of a sequence of complex numbers. (Contributed by NM, 28-Aug-2005) (Revised by Mario Carneiro, 28-Apr-2015)

Ref Expression
Assertion climcl
|- ( F ~~> A -> A e. CC )

Proof

Step Hyp Ref Expression
1 climrel
 |-  Rel ~~>
2 1 brrelex1i
 |-  ( F ~~> A -> F e. _V )
3 eqidd
 |-  ( ( F ~~> A /\ k e. ZZ ) -> ( F ` k ) = ( F ` k ) )
4 2 3 clim
 |-  ( F ~~> A -> ( F ~~> A <-> ( A e. CC /\ A. x e. RR+ E. j e. ZZ A. k e. ( ZZ>= ` j ) ( ( F ` k ) e. CC /\ ( abs ` ( ( F ` k ) - A ) ) < x ) ) ) )
5 4 ibi
 |-  ( F ~~> A -> ( A e. CC /\ A. x e. RR+ E. j e. ZZ A. k e. ( ZZ>= ` j ) ( ( F ` k ) e. CC /\ ( abs ` ( ( F ` k ) - A ) ) < x ) ) )
6 5 simpld
 |-  ( F ~~> A -> A e. CC )