Using mubuild to compile lambda expresion into a class library

The project I am working on requires me to build a project into a class library using the msbuild command via command line. When the compiler gets to a predicate function it returns error BC30201 Expression Expected. I have been able to build the project as a Form project however whenever I try building as a class library the error occurs. The code that keeps falling over is below.

I have Option Strict set to Off.

Can anyone advise as to how to fix the error?

PrivateFunctionSearchStrList(ByValStrAsString)AsSystem.Predicate(OfString)ReturnFunction(myStr AsString)IfStr= myStr ThenReturnTrueEndIfReturnFalseEndFunctionEndFunction