# How to get the expression of a special function?

How to get the expression of a special function? Like gamma function:

 Gamma[z]=Integrate[t^(z-1)/e^t, {t, 0, Infinity}]


reps = Entity["MathematicalFunction", "Gamma"][
"IntegralRepresentations"]


reps[[2]][z]


EDIT: Activating all except Integrate

Activate[reps[[2]][z], Except[Integrate]]


EDIT: For some functions, many of the properties may be missing. For example, for Hypergeometric2F1

properties = Select[
Entity["MathematicalFunction"]["Properties"],
FreeQ[
Entity["MathematicalFunction", "Hypergeometric2F1"][#],
Missing] &];

Length /@ {Entity["MathematicalFunction"]["Properties"], properties}

(* {54, 7} *)

Manipulate[
Entity["MathematicalFunction",
"Hypergeometric2F1"][prop],
{{prop, EntityProperty["MathematicalFunction",

In this case, the most useful available properties are the RelatedFunctions and Wolfram Functions Site link