% --- start of displayed preamble in the book --- input boxes % --- end of displayed preamble in the book --- defaultfont:="ptmr8r"; warningcheck:=0; beginfig(1) boxjoin(a.se=b.nw); boxit.one("One"); boxit.two("Two"); drawboxed(one,two); drawarrow one.n{up}..two.n; endfig; end;