code: def mrv_max1(f, g, exps, x):
      """Computes the maximum of two sets of expressions f and g, which
      are in the same comparability class, i.e. mrv_max1() compares (two elements of)
      f and g and returns the set, which is in the higher comparability class
      of the union of both, if they have the same order of variation.
      Also returns exps, with the appropriate substitutions made.
      """
      u, b = f.union(g, exps)
      return mrv_max3(f, g.do_subs(exps), g, f.do_subs(exps), u, b, x)
  
imports: from functools import reduce
  from sympy.core import Basic, S, Mul, PoleError, expand_mul
  from sympy.core.cache import cacheit
  from sympy.core.intfunc import ilcm
  from sympy.core.numbers import I, oo
  from sympy.core.symbol import Dummy, Wild
  from sympy.core.traversal import bottom_up
  from sympy.functions import log, exp, sign
  from sympy.series.order import Order
  from sympy.utilities.exceptions import SymPyDeprecationWarning
  from sympy.utilities.misc import debug_decorator
  from sympy.utilities.timeutils import timethis
label_desc: Use image node_id 4 for calling a global function with example usage: mrv_max1(f, g, exps, x) and returns: mrv_max3