complex apply syntax

3.11: adda/complex apply syntax:
. if functions can return functions,
eg f x x = f(x)(x) = g(x) = y,
what about prefix functions returning biops? eg:
x f(x) y = x g y = g(x,y) .
. need to be careful about where to draw the line between
writer's expressiveness,
and reader's sanity .