#!/usr/bin/perl
use strict;
use warnings;

use XML::LibXSLT;
use XML::LibXML;

my $parser = XML::LibXML->new();

my $mathml = $parser->parse_string( do { local $/; <> } );

my $xform_src = $parser->parse_fh( \*DATA );

my $xform = XML::LibXSLT->new()->parse_stylesheet( $xform_src );

my $results = $xform->transform( $mathml );

print $xform->output_string( $results );

__END__
paste stylesheet here...