Here is a rough approach, done by recursing through the MathML expression tree, converting from prefix to infix notation. 
use strict;
use XML::Twig;
 
my %binop = qw(divide / power ^);
my %down1 = qw(unit 1 math 1 apply 1);
my %units = qw(joule J meter m);
 
# Recurse through the ML tree, finding the binary operators.
sub recurse {
   my ($e) = shift;
   my $tag = $e->gi;
   if (exists $binop{$tag}) {
      my $p1 = $e->next_sibling;
      my $p2 = $p1->next_sibling if defined($p1);
      recurse($p1) if defined($p1);
      print $binop{$tag};
      recurse($p2) if defined($p2);
   } elsif (exists $down1{$tag}) {
      my $child = $e->first_child;
      recurse($child) if defined($child);
   } elsif ($tag eq "cn") {
      print $e->text;
   } elsif ($tag eq "ci") {
      my $txt = $e->text;
      if ($units{$txt}) {
         print $units{$txt};
      } else {
         print $txt;
      }
   } else {
      print $tag;
   }
}
 
# Uncomment if you really don't want to see an infix operator for the 
+power.
# $binop{power} = "";
 
my $t= XML::Twig->new();
my $txt = q{
<unit>
   <math>
     <apply>
       <divide/>
       <ci>joule</ci>
         <apply>
           <power/>
           <ci>meter</ci>
           <cn>2</cn>
         </apply>
     </apply>
   </math>
 </unit>
};
$t->parse($txt);
my $root= $t->root;
recurse($root);
print "\n";

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In reply to Re: MathML 2 ascii? by tall_man
in thread MathML 2 ascii? by mikeyo

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