matrix multiplication



Hello,

I try multiply matrices, but te result is strange to me, see

(%i1) matrix_element_mult: ".";
(%o1)                                  .
(%i2) matrix([A],[0],[0]) . matrix([W]) . matrix([E]);
                                 [ A ]
                                 [   ]
(%o2)                            [ 0 ] . W . E
                                 [   ]
                                 [ 0 ]

Why above result is not expanded? If I use braces around (see below) 
then it works as expected, why? Is it a bug? What is the reason 
for this behavior?

(%i3) (matrix([A],[0],[0]) . matrix([W])) . matrix([E]);
                                 [ A . W . E ]
                                 [           ]
(%o3)                            [     0     ]
                                 [           ]
                                 [     0     ]


This not work
(%i4) expand(matrix([A],[0],[0]) . matrix([W]) . matrix([E]));
                                 [ A ]
                                 [   ]
(%o4)                            [ 0 ] . W . E
                                 [   ]
                                 [ 0 ]

Zbigniew