private bool _IsSimple()
{
var byNumTrue = AllowedValues
.GroupBy(av => av.Count(av => av));
if (byNumTrue.Count() != 2)
{
return(false);
}
if (byNumTrue.SingleOrDefault(bnt => bnt.Key == 9)?.Count() != 13)
{
return(false);
}
if (byNumTrue.SingleOrDefault(bnt => bnt.Key == 1)?.Count() != 1)
{
return(false);
}
return(true);
}