Update FSM Chapter

source/finite-state-machines/ch-finite-state-machines.ptx

@@ -3,15 +3,18 @@
   <title>Finite State Machines</title>
 
   <introduction>
-    <p>
-      In this chapter, we explore a powerful abstract model: <b>finite-state machine</b> (<em>finite
-      automata</em>). Beyond its theory, we'll see how to use SageMath to define, model, then build,
-      visualize and run an example of a state machine to solve a real-world problem.</p>
+    <p> In this chapter, we explore a powerful abstract model: <em>finite-state machines</em>.
+      Beyond the theory, we'll see how to use <term>Sage</term> to define, model and build, then
+      visualize and run a few examples of state machines to solve real-world problems.</p>
     <aside>
       <title>Notes</title>
       <p>
-        State machines are often associated with tasks in relation with digital computers. However, the vast domain of applications of state machines extends from simple simulations to full control of complex industrial processes. These tasks can vary in complexity, be as simple as a parity check
-        or a complex as managing traffic patterns, and natural language recognition and processing.</p>
+        State machines are often associated with tasks in relation with system designs (circuits and
+        digital computers, algorithms, etc.) However, the vast and rich domain of applications of
+        state machines extends far beyond simple simulations to full control logic of complex
+        industrial processes and workflows. These tasks can vary in complexity, be as simple as a
+        parity check or a complex as managing traffic patterns, a programming language compiler, or
+        natural language recognition and processing.</p>
     </aside>
   </introduction>
 

source/finite-state-machines/sec-extended-example.ptx

@@ -1,6 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <section xml:id="sec-extended-example" xmlns:xi="http://www.w3.org/2001/XInclude" xml:lang="en">
     <title>FSM in Action</title>
+    <!-- TODO. revisit once the changes of the previous section is finalized -->
     <introduction>
         <title>Controlling Traffic Lights and Pedestrian Crossing Signals</title>
         <p>