Consider the following statements regarding Nyquist stability criteria

1. Nyquist plot will encircle the critical point as many as the number of times as the difference between poles and zeros of the characteristic equation.

2. For an open-loop stable system, for the closed-loop stability number of encirclements in the clockwise direction should be equal to number of zeros of the characteristic equation.

3. In Nyquist stability criteria encirclement is considered positive in a counter-clockwise direction.

Which of the above statement(s) is/are correct?