def dup_mul_term(f, c, i, K):
 if ((not c) or (not f)):
  return []
 else:
  return ([(cf * c) for cf in f] + ([K.zero] * i))

def dup_mul_term ( f , c , i , K ) : if ( ( not c ) or ( not f ) ) : return [ ] else : return ( [ ( cf * c ) for cf in f ] + ( [ K . zero ] * i ) )
multiply f by c*x**i in k[x] .