How to Declare and Define an Char data type variable in F# ?

// AbundantCode F# Tutorials and Code snippets
open System
[<EntryPoint>]
let main argv = 
    //How to Declare and Define an Float data type variable in F# ?
    let charvariable = 'A'
    Console.WriteLine(charvariable)
    let retval = Console.ReadLine()
    0 // return an integer exit code
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