alt/error_type_unk_alt6.nit:19,10--13: Type error: class Fail not found in module error_type_unk_alt6.
alt/error_type_unk_alt6.nit:22,17--20: Type error: class Fail not found in module error_type_unk_alt6.
alt/error_type_unk_alt6.nit:23,7--11: Error: Method '+' doesn't exists in Bool.