The article discusses the possibility of expressing reachability properties in TLA⁺, a topic that was previously thought to be unexpressible. Reachability properties refer to the ability to make a certain condition true, even if it's not actually chosen. The author revisits a section from Lamport's book, "A Science of Concurrent Programs", which explains how to express possibility and accuracy properties in TLA⁺, and provides an explanation of the concept in a more understandable way. The article aims to clarify the use of the ENABLED operator in TLA⁺, which is crucial in expressing reachability properties, and will explore two key questions related to this topic, providing a deeper understanding of how to express possibility properties in TLA⁺.