{
try {
/*new*/ matcher = null;
/*new*/ Replacer r = getReplacer(newExpr);
/*new*/ String newResult = null;
/*new*/ synchronized (r) { newResult = r.replace(input); }
//*old*/ String oldResult = perl5.substitute(oldExpr, input);
//*cmp*/ if (!newResult.equals(oldResult)) {
//*cmp*/ showError("substitute disagreement!"+
//*cmp*/ "\n\toldExpr=" + StringUtils.findAndReplace