256 	struct Double yy, r;  in small_gam()  local
261 		yy = ratfun_gam(y - x0, 0);  in small_gam()
262 		return (yy.a + yy.b);  in small_gam()
266 	yy.a = r.a - 1;  in small_gam()
268 	r.b = yy.b = y - yy.a;  in small_gam()
271 	for (ym1 = y - 1; ym1 > left + x0; y = ym1--, yy.a--) {  in small_gam()
272 		t = r.a * yy.a;  in small_gam()
273 		r.b = r.a * yy.b + y * r.b;  in small_gam()
279 	yy = ratfun_gam(y - x0, 0);  in small_gam()
280 	y = r.b * (yy.a + yy.b) + r.a * yy.b;  in small_gam()
281 	y += yy.a * r.a;  in small_gam()