@Override
	public void execute(double t) {
		Matrix y = new ColumnMatrix(output.getDim());
		if (pi.isConnected()) {
			if (mi.isConnected()) {
				y = mi.getInput().times(-1);
				y = y.plus(pi.getInput());
			} else
				y = pi.getInput();
		} else {
			if (mi.isConnected())
				y = mi.getInput().times(-1);
		}
		try {
			output.setOutput(y);
		} catch (OrderException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}