198.41.0.7:
.fi
.P
+The DNS lookups are usually the bottleneck for this mode, but we can
+perform them in parallel. Simply pass the number of threads to the GHC
+runtime on the command line; for example, the following will perform
+25 lookups in parallel:
+.P
+.nf
+.I $ hath reversed +RTS -N25 <<< \(dq198.41.0.4/24\(dq
+198.41.0.4: a.root-servers.net.
+198.41.0.5:
+198.41.0.6: rs.internic.net.
+\(pc\(pc\(pc
+.fi
+.P
Each of the modes also supports a present-tense flavor; the following
are equivalent to their counterparts: \fBregex\fR, \fBreduce\fR,
\fBdupe\fR, \fBdiff\fR, \fBlist\fR, \fBreverse\fR.