Metamath Proof Explorer

Theorem seq1hcau

Description: A sequence on a Hilbert space is a Cauchy sequence if it converges. (Contributed by NM, 16-Aug-1999) (Revised by Mario Carneiro, 14-May-2014) (New usage is discouraged.)

		Ref	Expression
	Assertion	seq1hcau	\|- ( F : NN --> ~H -> ( F e. Cauchy <-> A. x e. RR+ E. y e. NN A. z e. ( ZZ>= ` y ) ( normh ` ( ( F ` y ) -h ( F ` z ) ) ) < x ) )

Proof

Step	Hyp	Ref	Expression
1		hcau	\|- ( F e. Cauchy <-> ( F : NN --> ~H /\ A. x e. RR+ E. y e. NN A. z e. ( ZZ>= ` y ) ( normh ` ( ( F ` y ) -h ( F ` z ) ) ) < x ) )
2	1	baib	\|- ( F : NN --> ~H -> ( F e. Cauchy <-> A. x e. RR+ E. y e. NN A. z e. ( ZZ>= ` y ) ( normh ` ( ( F ` y ) -h ( F ` z ) ) ) < x ) )

Step

Hyp

Ref

Expression

hcau

 |-  ( F e. Cauchy <-> ( F : NN --> ~H /\ A. x e. RR+ E. y e. NN A. z e. ( ZZ>= ` y ) ( normh ` ( ( F ` y ) -h ( F ` z ) ) ) < x ) )

baib

 |-  ( F : NN --> ~H -> ( F e. Cauchy <-> A. x e. RR+ E. y e. NN A. z e. ( ZZ>= ` y ) ( normh ` ( ( F ` y ) -h ( F ` z ) ) ) < x ) )