##
my $alternations = join '|', keys %xref;
my $regexp = qr/\b($alternations)\b/;
##
##
my( $abbrev ) = $raw_response =~ m/$regexp/;
my $std_response;
if( exists $xref{$abbrev} ) {
$std_response = $xref{$abbrev};
}
else {
die "No valid response found in <<$std_response>>";
}
print "$std_response\n";