def order_at_oo(a, d, t):
 if a.is_zero:
  return oo
 return (d.degree(t) - a.degree(t))

def order_at_oo ( a , d , t ) : if a . is_zero : return oo return ( d . degree ( t ) - a . degree ( t ) )
computes the order of a/d at oo .