class A_X_A_X(a1: A; x1: X; a2: A; x2: X) -- check permutations

inherit
   ANY
      redefine out end

feature

   out: STRING
      do
         Result := "A_X_A_X"
      end

   write
      do
         print("[write] "+a1.out+"+"+x1.out+"+"+a2.out+"+"+x2.out+" -> "+out+"%N");
      end

end -- A_X_A_X