String add() {
	    cleanY = true;
	    minusOne = 1;
	    if (enterX) {
	        enterX = false;
	        minusOne = 1;
	        minusOne = 1;
	        y = x;
	        if (equalCalled) prevOpn = "";
	        prevOpn = "add";
	        equalCalled = false;
	        return format(x);
	    } else {
	        if (canCalculate) {
	            String output = equals();
	            y = result;
	            prevOpn = "add";
	            equalCalled = false;
	            return output;
	        } else {
	            prevOpn = "add";
	            equalCalled = false;
	            return format(x);
	        }
	    }
	}