def dmp_degree(f, u):
 if dmp_zero_p(f, u):
  return (- oo)
 else:
  return (len(f) - 1)

def dmp_degree ( f , u ) : if dmp_zero_p ( f , u ) : return ( - oo ) else : return ( len ( f ) - 1 )
return the leading degree of f in x_0 in k[x] .