#!/usr/bin/perl -w --
$s = '-abcdefgh'; $s =~ tr/abc//cd; print "s = '$s'\n";
$s = '-abcdefgh'; $s =~ tr/a-c//cd; print "s = '$s'\n";
$s = '-abcdefgh'; $s =~ tr'abc''cd; print "s = '$s'\n";
$s = '-abcdefgh'; $s =~ tr'a-c''cd; print "s = '$s'\n";

##</code><code>##

s = 'abc'
s = 'abc'
s = 'abc'
s = '-ac'