Imports System

Module ApplicationValidation

    Sub Main()
        ' Example usage
        Dim cityOfBirth As String = "sousse"
        Dim certificateCity As String = "Beja"
        Dim cnamPaperIssueDate As New DateTime(2022, 1, 1)

        ValidateApplication(cityOfBirth, certificateCity, cnamPaperIssueDate)
    End Sub

    Function ValidateBirthCertificate(cityOfBirth As String, certificateCity As String) As Boolean
        If cityOfBirth.ToLower() <> certificateCity.ToLower() Then
            Console.WriteLine("Application refused because Birth certificate must be issued in the city of birth.")
            Return False
        End If
        Return True
    End Function

    Function ValidateCnamPaper(issueDate As DateTime) As Boolean
        Dim sixMonthsAgo As DateTime = DateTime.Now.AddMonths(-6)
        If issueDate < sixMonthsAgo Then
            Console.WriteLine("Application refused because CNAM paper must be issued within the last six months.")
            Return False
        End If
        Return True
    End Function

    Sub ValidateApplication(cityOfBirth As String, certificateCity As String, issueDate As DateTime)
        ' Using AndAlso to ensure short-circuiting
        If ValidateBirthCertificate(cityOfBirth, certificateCity) AndAlso ValidateCnamPaper(issueDate) Then
            Console.WriteLine("Application is valid.")
        Else
            Console.WriteLine("Application is not valid.")
        End If
    End Sub

End Module