code: def sig_key(s, order):
      """
      Key for comparing two signatures.
  
      s = (m, k), t = (n, l)
  
      s < t iff [k > l] or [k == l and m < n]
      s > t otherwise
      """
      return (-s[1], order(s[0]))
  
imports: from sympy.core.symbol import Dummy
  from sympy.polys.monomials import monomial_mul, monomial_lcm, monomial_divides, term_div
  from sympy.polys.orderings import lex
  from sympy.polys.polyerrors import DomainError
  from sympy.polys.polyconfig import query
label_desc: Use image node_id 10 for calling a global function with example usage: sig_key(s, order) and returns: unknown,  order