public int getLow(int symbol) {
		checkSymbolInRange(symbol);
		int low   = freqTable.getLow (symbol);
		int high  = freqTable.getHigh(symbol);
		int total = freqTable.getTotal();
		if (!(0 <= low && low <= high && high <= total))
			throw new IllegalStateException("Symbol low cumulative frequency out of range");
		return low;
	}