tcfail019.hs:20: No instance for:
		     `B [a{-anU-}]'
    tcfail019.hs:20:
	in an instance declaration
    When checking methods of an instance declaration
 
tcfail019.hs:20: No instance for:
		     `C [a{-anU-}]'
    tcfail019.hs:20:
	in an instance declaration
    When checking methods of an instance declaration
 
tcfail019.hs:20: No instance for:
		     `B [a{-anU-}]'
    tcfail019.hs:20:
	in an instance declaration
    When checking superclass constraints of an instance declaration
 
tcfail019.hs:20: No instance for:
		     `C [a{-anU-}]'
    tcfail019.hs:20:
	in an instance declaration
    When checking superclass constraints of an instance declaration


Compilation had errors