code: def unify_var(var, x, s, **fns):
      if var in s:
          yield from unify(s[var], x, s, **fns)
      elif occur_check(var, x):
          pass
      elif isinstance(var, CondVariable) and var.valid(x):
          yield assoc(s, var, x)
      elif isinstance(var, Variable):
          yield assoc(s, var, x)
  
imports: from sympy.utilities.iterables import kbins
label_desc: Use image node_id 2 for calling a global function with example usage: unify_var(var, x, s) without return types