A more thorough explanation:

A functional analog is a different material, such as a chemical or DNA sequence, that produces the same result as the specified material when used in a certain way. This term is commonly used in patents to prevent others from copying their innovations without technically infringing their exclusive rights.

• A patent for a new drug may include a functional analog, which is a similar chemical compound that produces the same therapeutic effect as the original drug.
• A patent for a new electronic device may include a functional analog, which is a different component that performs the same function as the original component.

These examples illustrate how a functional analog can be used to protect a patent holder's exclusive rights. By including analogs in their claims, they can prevent others from creating similar products or processes that produce the same result.