protected void reduce(Integer ruleIndex) {
if (DEBUG)
dump("reduce "+ruleIndex);
Rule rule = getParserTables().getSyntax().getRule(ruleIndex.intValue());
pop(rule.rightSize()); // pop count of elements on right side
semanticReduce(rule);
String nonterminal = rule.getNonterminal();
push(getParserTables().getGotoState(top(), nonterminal), result, range);