more tweaks

Author: michaelficarra

spec.html

@@ -409,7 +409,7 @@ <h1>Number value</h1>
 
     <emu-clause id="sec-terms-and-definitions-number-type">
       <h1>Number type</h1>
-      <p>set of all possible Number values including the special NaN (“not a number”) value, positive infinity, and negative infinity</p>
+      <p>set of all possible Number values including *NaN* (“not a number”), *+∞*<sub>𝔽</sub> (positive infinity), and *-∞*<sub>𝔽</sub> (negative infinity)</p>
     </emu-clause>
 
     <emu-clause id="sec-number-object">