if you have 1.0/4.0 the compiler will treat it like 0.25 anyway, but for 1/4 take care for type conversion

if that plot is ok for this value you can use subs(Pi=Pi + 1e-12, %)

Actually I am a bit astonished: you want to write a thesis and instead of scanning your literature for methods and models you ask for software? If your terminus is standard than even Google might help and already the first entry leads to Wikipedia ... Anyway ... if I recall readings & discussions in Economics vaguely but correctly the magic word is utility function and you want to estimate a pdf from 'bins', your 'extremes' stand for the tails. You have to decide for models (plus have in mind what J Tarr told you), software is the least aspect ... Hope it helps ...

Thx! Ok, I can follow. The other is something which worked in older versions (0

J:=int(whatever);
A:=unapply( J, x,y,z);
Then A is a function of x,y,z for the expression given by the integral

  V:=convert(VAR,rational);
  simplify(V,size);
  length(V); # gives me 1298 characters using Maple 11