C# List issue, inclusive list

[defkon]

I have an issue and I can't seem to resolve it basically I have two list of int one which may or not include the other, and I need to draw an if condition just to check among the incoming list which set of the int it is coming from and make a decision so I have used so I have a boolean function\[code\]public bool firstiterate(){ var listint= new List<int>(){1,2,3,4}; var incomingint= returned.Select(s=s.ref); if(incoming.All(listint.Contains) { //dosomething }}\[/code\]and the second function as:\[code\]public bool seconditerate(){ var listint= new List<int>(){1,2,3,4}; var incomingint= returned.Select(s=s.ref); if(incoming.Any(listint.Contains) && !incoming.All(listint.Contains) { //dosomething }}\[/code\]but all my booleans are returning null on all cases even though either one should return something, What am I doing wrong. any help would be welcome.Thanks