On upper and lower ( τ1,τ2 )-precontinuous multifunctions
Chawalit Boonpok, Chokchai Viriyapong, Montri Thongmoon · Journal of Mathematics and Computer Science · 2018
This paper deals with the concepts of upper and lower \((\tau_1,\tau_2)\)-precontinuous multifunctions. Some characterizations of upper and lower \((\tau_1,\tau_2)\)-precontinuous multifunctions are investigated. The relationships between upper and lower \((\tau_1,\tau_2)\)-precontinuous multifunctions and the other types of continuity are discussed.