<?php

$ligne = 020860101347;

function verifSomme($ligne, $somme = 0) {
  	$factors = array(7,3,1);
  	$result = 0;
  	$offset = 0;
  	foreach(str_split($ligne,1) as $char) {
  		if($char == '<') {
  			$char = 0;
 		//ord('A') <= ord($char) <= ord('Z')
 		} elseif(ord($char) >= 65 && ord($char) <= 90) {
 			$char = ord($char) - 55;
 		} elseif($char >= 0 && $char <= 9) {
 			$char = intval($char);
 		} else {
 			die('caractère hors borne');
 		}
 		$result += $char*$factors[$offset%3];
 		$offset++;
 	}
 	echo $result % 10;
 	return (($result % 10) == $somme);
 }

?>