code: def s_poly(cp):
      """
      Compute the S-polynomial of a critical pair.
  
      The S-polynomial of a critical pair cp is cp[1] * cp[2] - cp[4] * cp[5].
      """
      return lbp_sub(
          lbp_mul_term(cp[2], cp[1]), lbp_mul_term(cp[5], cp[4])
      )
  
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 19 for calling a global function with example usage: s_poly(cp) and returns: lbp_sub