currying.fs

    let withdrawWithAudit = withdraw |> auditAs "withdraw" Auditing.fileSystem
    let depositWithAudit = deposit |> auditAs "deposit" Auditing.fileSystem

    while true do
        let action =
            Console.WriteLine()
            printfn "Current balance is £%M" account.Balance
            Console.Write "(d)eposit, (w)ithdraw or e(x)it: "
            Console.ReadLine()

        if action = "x" then Environment.Exit 0

        let amount =
            Console.Write "Amount: "
            Console.ReadLine() |> Decimal.Parse

        // Mutate account value via an expression
        account <-
            if action = "d" then account |> depositWithAudit amount
            elif action = "w" then account |> withdrawWithAudit amount
            else account