Caesar Cipher in C# (with Linq)

Rot13.cs

if (args?.Count() > 0)
    Console.WriteLine(args[0].Select(c =>
            c switch
            {
                >= 'a' and <= 'm' or >= 'A' and <= 'M' => (char)(c + 13),
                >= 'n' and <= 'z' or >= 'N' and <= 'Z' => (char)(c - 13),
                _ => c
            }
        ).ToArray());

Using top-level statements (see https://learn.microsoft.com/en-us/dotnet/csharp/whats-new/tutorials/top-level-statements) and Linq along with pattern matching (see https://learn.microsoft.com/en-us/dotnet/csharp/fundamentals/functional/pattern-matching)

The Challenge

Caesar Cipher in the least procedural way (with extra points for the least number of semi-colons).

TDD

> Rot13 Test13!
> Grfg13!
> Rot13 Grfg13!
> Test13!