AppellF1[a, , , c, x, y] is the Appell hypergeometric function of two variables .
Mathematical function (see Section A.3.10).
has series expansion .
reduces to when or .
AppellF1[a, , , c, x, y] has singular lines in two-variable complex space at and , and has branch cut discontinuities along the rays from to in and .
FullSimplify and FunctionExpand include transformation rules for AppellF1.
See The Mathematica Book: Section 3.2.10.
See also: Hypergeometric2F1.