F# equivalent of `is` keyword in C#?

Question

My first F# day. If I have this:

let cat = Animal()

Now how do I check at later stage if cat is Animal

Answer 1

I know I'm late. If you try to test the type of a collection in fsi with :? it will give an error, if the item types do not match. E.g.

let squares = seq { for x in 1 .. 15 -> x * x }  
squares :? list ;;   // will give false  
squares :? list ;; // error FS0193: Type constraint mismatch

Wrapping in a function like Daniels is<'T> works.