illegal recursion in supertypes:
   --> type A.U (_t4ae5d31e) in A.m3
   --> type A.T (_taf464afb) in A.i3
   --> type A.T (_ta15b1e0b) in Main.m3
   --> type A.U (_t7943788c) in A.i3
illegal recursion in supertypes:
   --> type A.T (_ta15b1e0b) in Main.m3
   --> type A.U (_t7943788c) in A.i3
   --> type A.U (_t4ae5d31e) in A.m3
   --> type A.T (_taf464afb) in A.i3

Fatal Error: incomplete program

