In this paper, strong pre-open and strong pre-close sets were introduced in topological spaces and their properties were researched.

在分明拓扑空间中引入强拟开集和强拟闭集的概念，并讨论了它们的性质。

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The brokerage arm of Fidelity Investments, the fund giant, three years ago extended its pre-open trading from 8 a.m. to 7 a.m.

FORBES: Magazine Article

Paul International Airport is open to pre-credentialed members of the media, but closed to the public.

WHITEHOUSE: The White House

This arrival is pooled for TV and correspondents and open to pre-credentialed still photographers.

WHITEHOUSE: Vice President's Schedule