Just so. We were generally aware of each other's work. My papers on drawing lines, circles, and ellipses on rasters, though, were barely connected to troff. Troff did not contain any drawing algorithms. That work was relegated to the rendering programs that interpreted ditroff output. Thus publication-quality rendering with support for thick lines was outsourced to Adobe and Mergenthaler. Various PostScript or ditroff postprocessors for screen-based terminals were written in house. These programs paid little or no attention to fonts and line widths. But the blit renderers made a tenuous connection between my ellipse algorithm and troff, since my work on the topic was stimulated by Rob's need for an ellipse generator. Doug