  Normal forms for wide classes of closed IL formulas were given in [4]. Here
we quantify asymptotically, in exact numbers, how wide those classes are. As a
consequence, we show that the "majority" of closed IL formulas have
GL-equivalents, and by that, they have the same normal forms as GL formulas.
Our approach is entirely syntactical, except for applying the results of [4].
As a byproduct we devise a convenient way of computing asymptotic behaviors of
somewhat general classes of formulas given by their grammar rules. Its
applications do not require any knowledge of the recurrence relations,
generating functions, or the asymptotic enumeration methods, as all these are
incorporated into two fundamental parameters.
