In our introduction to the SOLID Design Principles, we mentioned the Liskov Substitution Principle as one of the five principles specified. In this post we are going to dive into this design principle and work with a very simple example in C#. As you study the SOLID Design Principles, you will notice there is a great deal of overlap among the individual principles. While discussing the Liskov Substitution Principle, we are going to take a quick dive into the Interface Segregation Principle as well, but not overly so as the next post will discuss that more deeply. We will however take a look at how to segregate interfaces in pursuit of not violating the Liskov Substitution Principle.