class Client void Main Context context new Context var expression new

class Client
{
    void Main()
    {
        Context context = new Context();
 
        var expression = new NonterminalExpression();
        expression.Interpret(context);
 
    }
}
 
class Context
{
}
 
abstract class AbstractExpression
{
    public abstract void Interpret(Context context);
}
 
class TerminalExpression : AbstractExpression
{
    public override void Interpret(Context context)
    {
    }
}
 
class NonterminalExpression : AbstractExpression
{
    AbstractExpression expression1;
    AbstractExpression expression2;
    public override void Interpret(Context context)
    {
             
    }
}