code: def dup_sub_mul(f, g, h, K):
      """
      Returns ``f - g*h`` where ``f, g, h`` are in ``K[x]``.
  
      Examples
      ========
  
      >>> from sympy.polys import ring, ZZ
      >>> R, x = ring("x", ZZ)
  
      >>> R.dup_sub_mul(x**2 - 1, x - 2, x + 2)
      3
  
      """
      return dup_sub(f, dup_mul(g, h, K), K)
  
imports: from sympy.polys.densebasic import dup_slice, dup_LC, dmp_LC, dup_degree, dmp_degree, dup_strip, dmp_strip, dmp_zero_p, dmp_zero, dmp_one_p, dmp_one, dmp_ground, dmp_zeros
  from sympy.polys.polyerrors import ExactQuotientFailed, PolynomialDivisionFailed
label_desc: Use image node_id 29 for calling a global function with example usage: dup_sub_mul(f, g, h, K) and returns: dup_sub