1TROFF= vtroff -t 2 3print: trofftxt 4 vpr -t trofftxt 5 6troff: 7 /usr/ucb/soelim pxin?.n | tbl | ${TROFF} 8 9trofftxt: fig2.3.n 10 /usr/ucb/soelim pxin?.n | tbl | /usr/ucb/vtroff -t >trofftxt 11 12fig2.3.n: fig2.3.raw 13 sort fig2.3.raw >fig2.3.n 14