*Definition [#h328ca4a]
A sequence &ref(http://www.eaflux.com/imgtex/imgtex.fcgi?%5bres=100%5d%7b$x_n$%7d%25.png); is called s-convergent if and only if there is some point x such that for any semipreopen set A containing x, &ref(http://www.eaflux.com/imgtex/imgtex.fcgi?%5bres=100%5d%7b$x_n$%7d%25.png); is eventually in A.