| Affiliation: | Mathematical Institute, University of Wroclaw, pl. Grunwaldzki 2/4, 50-384 Wroclaw, Poland - Instituto de Matemáticas, UNAM, Circuito Exterior, Ciudad Universitaria, 04510 México, D. F., México ; Mathematical Institute, University of Wroclaw, pl. Grunwaldzki 2/4, 50-384 Wroclaw, Poland - Departamento de Matemáticas, Facultad de Ciencias, UNAM, Circuito Exterior, Ciudad Universitaria, 04510 México, D. F., México ; Instituto de Matemátic as, UNAM, Circuito Exterior, Ciudad Universitaria, 04510 México, D. F., México |
and 
it is shown that if the projection 
has its induced mapping 
open, then 
is 
-smooth. As a corollary, a characterization of dendrites in these terms is obtained.