prologues:=1; defaultfont:="Times-Roman"; beginfig(1) a=.8in; z0=(0,0); fill (z0+(0,2.8*a))--z0--(z0+(2*a,a))--(z0+(3*a,2*a))--(z0+(3*a,2.7*a))--cycle withcolor .7white; drawarrow (z0-(0.5*a,0))--(z0+(3.5*a,0)); drawarrow (z0-(0,0.5*a))--(z0+(0,3*a)); label.lrt("0", z0); label.bot("1", z0+(a,0)); label.bot("2", z0+(2*a,0)); label.bot("3", z0+(3*a,0)); label.ulft("0", z0); label.lft("1", z0+(0,a)); label.lft("2", z0+(0,2*a)); pickup pencircle scaled .1in; draw z0; draw z0+(a,a); draw z0+(2*a,a); draw z0+(3*a,2*a); pickup pencircle scaled .02in; draw (z0+(0,2.9*a))--z0--(z0+(2*a,a))--(z0+(3*a,2*a))--(z0+(3*a,2.8*a)); endfig; end