.ds . \fB.\fP .tr~ .ds . \fB.\fR . S1 - smaller in text .de S1 .nh .ps -1 .. . S2 - reverse S1 .de S2 .ps +1 .hy .. .de WS .sp \\$1 .. . H1 - start new section .de H1 .SH .. . H2 - after H1 title .de H2 .. . X1 - start of example .de X1 .nf .in +.3i .sp 4p .if t .tr -\(en .. . X2 - end of example .de X2 .sp 4p .tr -- .in -.3i .fi .. .de PG .PP ..