Properties of pre-I-open sets

In 1982, [5] have defined the notion of preopen sets. Ouite recently in 2002, [6] has defined pre neighbourhoods, pre-interior point, prelimit point, prederived set and prefrontier of set. For these sets we define the notion of pre-I-interior point, pre-I-limit point, and pre-I-frontier of a set using pre-I-open sets and pre-I-closed sets in ideal topological space. We also obtained a necessary and sufficient condition for an ideal topological space to be a pre-I-T1 space