.eo
.\" s -- setup document
.de _s
. \" configure initial options
. _nr mt 1i	\" margin top
. _nr mb 1i	\" margin bottom
. \" initialize document
. wh 0 _h
. wh -\n(mbu _f
. sp 1u		\" trigger header
. ns
. \" configure environments
. _e t		\" title
.  evc 0
.  ps +4p
.  vs +2p
.  ft B
.  ad c
. _e n		\" name (of author)
.  evc 0
.  nr sp 0.4v
.  ad c
. _e d		\" date
.  evc 0
.  nr sp 0.4v
.  ad c
. _e h		\" heading
.  evc 0
.  nr sp 0.6v
.  ps +1p
.  ft B
. _e s		\" section heading
.  evc 0
.  nr sp 0.6v
.  ft B
. _e p		\" paragraph
.  evc 0
.  nr sp 0.3v
.  nr ti 0.5c
.  ad b
. _e c		\" code listing
.  evc 0
.  nr sp 0.3v
.  nr in 0.5c
.  nf
.  in 0.5c
.  fam C
.  ps -1p
. _e
..
.\" _h -- page header
.de _h
' sp \n(mtu
..
.\" _f -- page footer
.de _f
' sp 1v
. tl ''%''
' bp
..
.\" _nr -- set default value
.de _nr
. if \n[\$1]=0 .nr \$1 \$2
..
.\" _e -- set environment
.de _e
. if '\n(_s'0' \{\
.  nr _s 1
.  _s
. \}
. br
. if !'\n[.ev]'0' \{\
.  nr \n[.ev]_sp \n(sp
.  nr \n[.ev]_in \n(in
.  nr \n[.ev]_ti \n(ti
.  ev
. \}
. ds penv \*[env]
. ds env \$1
. if !'\$1'' \{\
.  ev \$1
.  nr sp \n[\n[.ev]_sp]
.  nr in \n[\n[.ev]_in]
.  nr ti \n[\n[.ev]_ti]
.  sp \n(spu
.  in \n(inu
. \}
. _mb
..
.\" _mb -- margin bottom
.de _mb
. ie '\*[env]'n' .return
. el .if '\*[env]'d' .return
. ie '\*[penv]'t' .sp 1v
. el .ie '\*[penv]'n' .sp 1v
. el .if '\*[penv]'d' .sp 1v
..
.\" i -- italic
.de i
\$3\fI\$1\fP\$2
..
.\" x -- bold italic
.de x
\$3\f(BI\$1\fP\$2
..
.\" q -- quote
.de q
\$3\(lq\$1\(rq\$2
..
.\" t -- title
.de t
. _e t
..
.\" n -- name (of author)
.de n
. _e n
. if '\*[penv]'t' .sp 0.2v
..
.\" d -- date
.de d
. _e d
. if '\*[penv]'t' .sp 0.2v
. af mo 00
. af dy 00
. ie '\$1'' \n[year]-\n(mo-\n(dy
. el \$1
. af mo 1
. af dy 1
..
.\" h -- heading
.de h
. _e h
..
.\" s -- section heading
.de s
. _e s
..
.\" p -- paragraph
.de p
. _e p
. if '\*[penv]'p' .ti \n(tiu
..
.\" c -- code listing
.de c
. _e c
..
.ec