% --- start of displayed preamble in the book ---
input metaobj
% --- end of displayed preamble in the book ---
defaultfont:="ptmr8r";
warningcheck:=0;
beginfig(1)
newBox.m1(btex A etex);
newMatrix.mat(1,1)(m1);
mat.c=origin;
drawObj(mat);
endfig;
end;