Imports System Imports uCalcSoftware Public Module Program Public Sub Main() Dim uc As New uCalc() uc.DefineConstant("LOCKED_VAL = 1000") Console.WriteLine($"Initial value: {uc.Eval("LOCKED_VAL")}") '// 1. End-user attempts to assign a value. This should fail. uc.Eval("LOCKED_VAL = 2000") Console.WriteLine($"Error after assignment attempt: {uc.Error.Message}") Console.WriteLine($"Value remains unchanged: {uc.Eval("LOCKED_VAL")}") End Sub End Module