F := (s-t)*(-1+s)*(t-x)/s/t/ (-s*t+2*s^2*t+2*t^2+2*x*s-3*s*t^2-3*x*t-3*x*s^2+4*x*s*t): P_, S_, T_ := op(op( Mgfun:-creative_telescoping(F, x::diff, [s::diff, t::diff]) )): P := DEtools[de2diffop](P_, _F(x), [Dx,x]); S := eval(S_, _f = unapply(F, x, s, t)): T := eval(T_, _f = unapply(F, x, s, t)):