Let x0 of type ι be given.
Let x1 of type ι be given.
Apply set_ext with
prim2 x0 x1,
prim2 x1 x0 leaving 2 subgoals.
The subproof is completed by applying unknownprop_eefafd7b52dc937ce9b3f71f22e639590455bb88b18ae8f6fa4d3714983d5bb8 with x0, x1.
The subproof is completed by applying unknownprop_eefafd7b52dc937ce9b3f71f22e639590455bb88b18ae8f6fa4d3714983d5bb8 with x1, x0.