Effective validator count: actual set size for variable, V for fixed.
4.10. Variable Validators (GP#514)
In jar1, the active validator set size and core count can vary. The effective validator count determines which protocol constants scale dynamically.
def
Jar.effectiveValCount.{u_1} [j : Jar.JarConfig] {α : Type u_1} (validators : Array α) : NatJar.effectiveValCount.{u_1} [j : Jar.JarConfig] {α : Type u_1} (validators : Array α) : Nat