private void minimisedExpression() {
		String ch = "";
		for (int i = 0; i < arrayList.size(); i++) {
			char tabChar[] = arrayList.get(i).nodes.toCharArray();
			for (int j = 0; j < tabChar.length; j++) {
				if (tabChar[j] == '0') {
					ch = ch + "!" + ordrVar.charAt(j);
					if (!endOfTerms(arrayList.get(i).nodes, j))
						ch = ch + "*";
				} else {
					if (tabChar[j] == '1') {
						ch = ch + ordrVar.charAt(j);
						if (!endOfTerms(arrayList.get(i).nodes, j))
							ch = ch + "*";
					}
				}

			}
			if (i != arrayList.size() - 1)
				ch = ch + "+";
		}
		minimisedExpression = ch;
	}