%% syntaxe : k n p binomiale --> Cnk p^k (1-p)^(n-k)
/binomiale {   
3 dict begin
   /p exch def
   /n exch def
   /k exch def
   n k Cnp 
   p k exp
   mul
   1 p sub
   n k sub
   exp
   mul
end
} def