DEFINITION MODULE IncGamma;

   (*  EXPORT QUALIFIED GammP, GammQ, GSer, GCF, ErF, ErFC, ErFCC; *)

   PROCEDURE GammP(a, x: REAL): REAL; 
   (*
     Returns the incomplete gamma function P(a,x)
   *)

   PROCEDURE GammQ(a, x: REAL): REAL; 
   (*
     Returns the incomplete gamma function Q(a,x) = 1-P(a,x).
   *)

   PROCEDURE GSer(    a,      x:   REAL; 
                  VAR gamSer, gLn: REAL); 
   (*
     Returns the incomplete gamma function P(a,x) evaluated
     by its series representation as gamSer.  Also returns ln("Gamma")(a)
     as gLn.
   *)

   PROCEDURE GCF(    a,      x:   REAL; 
                 VAR gammCF, gLn: REAL); 
   (*
     Returns the incomplete gamma function Q(a,x) evaluated by its continued 
     fraction representation as gammCF.  Also returns ln "Gamma" (a)
     as gLn.
   *)

   PROCEDURE ErF(x: REAL): REAL; 
   (*
     Returns the error function oxerf(x).
   *)

   PROCEDURE ErFC(x: REAL): REAL; 
   (*
     Returns the complementary error function oxerfc(x).
   *)

   PROCEDURE ErFCC(x: REAL): REAL; 
   (*
     Returns the complementary error function oxerfc(x)
     with fractional error everywhere less than 1.2x10^-7.
   *)

END IncGamma.