
/**  Hypergeometric Cancelation Theorems  **/
/*A: J Gottschalk */
/*S: University of Western Australia, Nedlands 6009, Australia*/
/*D: January, 1988 */
/*K: Ghg, Cancelation*/

#_:    Comm
Ghg_:  Tier

Ghg[$p,$q,#[$x,$$a],#[$y_=$y = $x & ~Natp[1-$y],$$b],$z] : \
				 Ghg[$p-1,$q-1,#[$$a],#[$$b],$z]
Ghg[$p,1,#[$x,$$a],#[$y_=$y = $x & ~Natp[1-$y]],$z] : Ghg[$p-1,0,#[$$a],#[],$z]
Ghg[1,$q,#[$x],#[$y_=$y = $x & ~Natp[1-$y],$$b],$z] : Ghg[0,$q-1,#[],#[$$b],$z]
Ghg[1,1,#[$x],#[$y_=$y = $x & ~Natp[1-$y]],$z]      : Ghg[0,0,#[],#[],$z]

/*I: The $y_=$y=$x is used to overcome the bug described in 
	bugs/pattern_matcher. */

/*R: [AS 15.1; Slater, Generalized Hypergeometric Functions,
     Cambridge University Press,1966] */

