private void addProductions(Collection productions) {
		Iterator it = productions.iterator();
		if (!it.hasNext())
			return;
		GrammarTableModel model = table.getGrammarModel();
		int min = 1000000000, max = 0;
		while (it.hasNext()) {
			Production p = (Production) it.next();
			int row = model.addProduction(p);
			min = Math.min(min, row);
			max = Math.max(max, row);
		}
		table.setRowSelectionInterval(min, max);
	}