T7881.hs:7:6: warning: [-Wempty-enumerations (in -Wdefault)]
    Enumeration is empty

T7881.hs:25:6: warning: [-Wempty-enumerations (in -Wdefault)]
    Enumeration is empty

T7881.hs:31:6: warning: [-Wempty-enumerations (in -Wdefault)]
    Enumeration is empty