This is may be a philosophical question. But sometimes Maple suprises me when telling it to "simplify" expression. As in this example.
For me, the original result is "simpler". (Not only smaller leaf count, but it has one special function, vs. two: Legendre and Gamma). But may be Maple considers hypergeom always more "complex" than any other?
That is why I use simplify(expr,size) because I am scared of simplify without any option, as I have little idea how it decides which is simpler.
Any thoughts from the experts on how Maple decided to simplify something when no option is used? What kinds of rules it uses to decide how to transform the expression?