About Chapter13——Declaring Delegate Types

[Jia-NaiLiang]

https://essentialcsharp.com/declaring-delegate-types#declaring-delegate-types

I am a bit confused about whether this code example is correct.
When I copy it into VS Code (with the C# extension), it triggers error CS1961.

[BenjaminMichaelis]

@Jia-NaiLiang Ah great find! I think this should be public delegate TResult Func<in T1, in T2, out TResult>(T1 arg1, T2 arg2); - I will get the site updated