The relation between the formation of a unique system and the upward-bending parameter a of 2-D(η, μ)InFq vs In M in relativistic heavy-ion collisions is discussed. It is argued that the correlation between the value of upward-bending parameter a for individual events and the value for the same events of some other quantity, e.g., K/π ratio, commonly used as quark-gluon plasma signal can be utilized to increase the reliabili...