Upper and Lower Contra-$(\tau_1,\tau_2)$-continuity

This paper presents new classes of multifunctions between bitopological spaces, namely upper contra-$(\tau_1,\tau_2)$-continuous multifunctions and lower contra-$(\tau_1,\tau_2)$-continuous multifunctions. Moreover, several characterizations and some properties concerning upper contra-$(\tau_1,\tau_2)$-continuous multifunctions and lower contra-$(\tau_1,\tau_2)$-continuous multifunctions are investigated.