title: Sequential Consistency in Distributed Systems
body: <p>I am learning Sequential Consistency in Distributed Systems but just could not understand the terms explained. I would appreciate if someone can shed some light in layman's term on why (a) and (c) below are sequentially consistent and (b) is not.
  Thanks.<img src="https://i.stack.imgur.com/1WFwa.jpg" alt="enter image description here"></p>