A new generalization of Calbrix-Troallic's theorem

摘要

The paper introduces new concepts of lower pseudo-quasicontinuity and lower covering categorical cliquishness for multi-value maps and use them to set a general theorem on the points of jointly continuity of mappings f : X ×Y → Z, yielding as a partial case a previous result of the authors as well as a result of A. Bouziad and J.P. Troallic.