interpretation "basic pair relation for subsets" 'Vdash2 x y c = (fun21 (concr ?) ?? (relS c) x y).
interpretation "basic pair relation for subsets (non applied)" 'Vdash c = (fun21 ??? (relS c)).
*)
interpretation "basic pair relation for subsets" 'Vdash2 x y c = (fun21 (concr ?) ?? (relS c) x y).
interpretation "basic pair relation for subsets (non applied)" 'Vdash c = (fun21 ??? (relS c)).
*)