3 http://hdl.handle.net/10338.dmlcz/116808 3 Summaries of articles published in this issue http://hdl.handle.net/10338.dmlcz/100923 Summaries of articles published in this issue Simultaneous extensions of two functionals http://hdl.handle.net/10338.dmlcz/100922 Simultaneous extensions of two functionals Openness of linear mappings in $LF$-spaces http://hdl.handle.net/10338.dmlcz/100921 Openness of linear mappings in $LF$-spaces On couples of line congruences with the projective connection having Rozenfeld image with the character smaller than 5 http://hdl.handle.net/10338.dmlcz/100920 On couples of line congruences with the projective connection having Rozenfeld image with the character smaller than 5