F# I want to look at the type of declaration specified in Interactive

F#Interactive displays the type along with the value.

>1;
value : int = 1
>Some1;
value:intoption=Some1
>printf;
value:(Printf.TextWriterFormat<'a>->'a) =<fun:[email protected]>

Then, is there a way to specify a type and check the declaration of that type?

Simply specifying the type name will display the type of constructor.

>Printf.TextWriterFormat<_>;;;
value: arg00:string->PrintfFormat<'a, System.IO.TextWriter, unit, unit>=
  <fun:[email protected]>
>Option<_>;;;

  Option<_>;;;
  ^^^^^^

stdin(7,1): error FS0039: no value or constructor 'Option' defined

Instead, I'd like to see a declaration of the type itself written in a .fsi file.

When you define a type on F#Interactive, you see something similar, so can you apply it to an existing type?

>type Foo=A of int|B with
-     member self.Hoge(x) = 1;

type Foo=
  | A of int
  | B
  with
    member Hoge:x:'a->int
  end

As you can see by typing in F#Interactive when you're curious about the type of function, if you look at the type declaration in the same way, you don't have to open a browser...