4l*dKl2ccH"ʭ6t_H8pnG[ƻb4}!2P=o\<_y-kCn1Ƈ]Qlm_ y+Ҥ_DPP;g8D+WkYcV2ukLm$TU K`5#uGo1)/nW60]U`>U_u<5gy 1šlҁh4Fih>uK~*8BϠ<:9 _\9 lykkفCi6<+ .s,OJƂ r\#.`YMwH ^/uz%X}l3Ntʱ_rr|=`'M>{`u0ط.Kt`#௰!h2}c2W#Bgb䕛@xt9Rٷ^6 $X{-hegyV!k8!'p䐸hzI; Wx\]]C{E-8C:aH8EI 7w fn?:C;GKU&_#=Knٲ!҉>M`kE.(dJ_J's<e`L_f2!dTC͔~ complexity of reasoning for it is precisely the same as for the standard modal logic (or, equivalently, for the Description Logic ALC), namely, it is PSpace-complete. In the second part of the talk, some results will be presented concerning the applications of this new modal logic to querying DL knowledge bases. As will be shown, for many interesting cases, it is possible to reduce the query answering problem to retrieving instances of pure ALC concepts. Some open problems in this direction will also be discussed. No special knowledge is required for understanding, beyond the acquaintance with the standard DLs like ALC and that it is a notational variant of the modal logic K. ++,,,