In this paper, we introduce the quasi 0-gliding hump property of sequence spaces and study a series of elementary properties of spaces of λ-multiplier convergent series.
Introduction.Let (X, T ) be a Hausdorff locally convex space, X * the topological dual space of (X, T ) and λ a scalar-valued sequence space. A series j x j in X is said to be λ-multiplier T -convergent if, for each (t j ) ∈ λ, there exists an x ∈ X such that the seriesLet c 00 be the scalar valued sequence space which are 0 eventually, the β-dual space of λ to be defined by: λ β = {(u j ) : j u j t j is convergence for each (t j ) ∈ λ}. It is obvious that if c 00 ⊆ λ, then [λ, λ β ] is a dual pair with respect to the bilinear pairing [ t, ū] = j u j t j , where t = (t j ) ∈ λ, ū = (u j ) ∈ λ β . Let τ (λ, λ β ) denote the Mackey topology of λ with respect to the dual pair [λ, λ β ], i.e., the topology of uniform convergent on all absolutely convex σ(λ β , λ)-compact subsets of λ β , and k(λ, λ β ) the topology of uniform convergent on all σ(λ β , λ)-compact subsets of λ β . It is clear that k(λ, λ β ) is stronger than τ (λ, λ β ).Lemma 1 [14]. Let c 00 ⊆ λ and τ 1 be a vector topology on λ β such that τ 1 is stronger than the coordinate convergence topology. Then the following states are equivalent:(1) B ⊆ λ β is τ 1 -compact;(2) B ⊆ λ β is τ 1 -sequentially compact.