metric space distance must obey some axioms
d(x,x)=0
d(x,y)=(0,infinity)
If p0=p1=……=pn-1, then the sample space isequally likely outcomes 0,1,…….n-1, then any event A is given by card (A) whichis card number or cardinality of A.
So the computation of probability devolveinto counting exercise.