[nikeee]

I was under the impression that they compile with /checked per default. TIL!

Regardless of that flag, Math.Abs will throw an OverflowException: https://referencesource.microsoft.com/#mscorlib/system/math....

[lazulicurio]

The default actually depends on project language IIRC. C# has overflow checking disabled by default, VB.net has it enabled by default. Not sure about F#.