Resultant of two equal forces may have the magnitude equal to one of the forces.

Price stability, to show inflation is controlled;Soundness and sustainability of public finances, through limits on government borrowing and national debt to avoid excessive deficit;Exchange-rate stability, through participation in the Exchange Rate Mechanism (ERM II) for at least two years without strong deviations from the ERM II central rate;Long-term interest rates, to assess the durability of the convergence achieved by fulfilling the other criteria