.
.de IX
.ie '\\n(.z'' .tm IX: \\$1 \\$2 \\$3 \\$4 \\$5 \\$6 \\$7 \\$8 \\$9	{\\n(PN}
.el \\!.IX \\$1 \\$2 \\$3 \\$4 \\$5 \\$6 \\$7 \\$8 \\$9	{\\n(PN}
..

This is a sample file to test the \fImakeindex\fP(1L) program, and see
.IX {indexing!programs!C language}
.IX {makeindex@\fImakeindex\fP(1L)}
.bp
.rs
.IX {Knuth}
.IX {typesetting!computer-aided}
how well if functions in the \fItroff\fP(1) environment.
