[STATEMENT]
lemma energy_graph_subsets_commute: 
  "energy_graph_subsets U W G = energy_graph_subsets W U G"
[PROOF STATE]
proof (prove)
goal (1 subgoal):
 1. energy_graph_subsets U W G = energy_graph_subsets W U G
[PROOF STEP]
by (simp add: energy_graph_subsets_def edge_density_commute)