-If only one file is specified, then it is compared to a file with the same name
-without the
-.I ".gz"
-extension. If two files are specified, then they are uncompressed if necessary
-and fed to
+If only
+.I file1
+is specified, it is compared to the uncompressed contents of
+.IR file1 ".gz."
+If two files are specified, their contents (uncompressed if necessary) are fed to