本文研究了连续d-cone的Sandwich性质,证明连续d-cone的Sandwich性质关于乘积和连续线性收缩封闭.特别地,本文证明了:设X是连续domain,C是连续d-cone,下述两条等价:(1)任给Scott连续映射∧q∧p,:X×C→-R+满足∧q≤∧p,若对任意x∈X,∧q(x,-),∧p(x,-):C→-R+分别是超线性的和子线性的,则存在Scott连续函数∧∧:X×C→-R+使得∧q≤∧(A)≤∧p且对任意x∈X有∧(A)(x,-):C→-R+是线性函数;(2)X是离散domain即X的任意两个不同元素不可比较.该结果回答了2009年Tix,Keimel和Plotkin提出的一个公开问题.
In this paper, we investigate the Sandwich property of continuous d-cones and show that the Sandwich property of continuous d-cones is closed under products and continuous retractions. Particularly, it is proved that for a continuous domain X and a continuous d-cone C, the following conditions are e- quivalent : (1) for two continuous maps q,p:X × C → R+with q ≤p, for any x ∈X,q(x,-),p(x,-): C→R+ are superlinear and sublinear respectively, then there exists a continuous function A :X × C→ R+ such that q ≤∧ ≤p and∧(x,-).-C→ R+ is linear for all∈ E X. (2) X is a discrete domain. This result answers an open question by Tix, Keimel and Plotkin in 2009.