It looks like a fairly powerful static analysis framework, well beyond what the C# type system can prove. Not sure what exactly it can do, but the static checker dialog box allows you to enable:<p><pre><code>  Implicit Non-Null Obligations
  Implicit Arithmetic Obligations
  Implicit Array Bounds Obligations
  Redundant Assumptions
</code></pre>
If it can do a good job of checking these statically, I'm impressed!