Clarify "valid floating-point number" definition

Author: sideshowbarker

source

@@ -4131,7 +4131,7 @@ a.setAttribute('href', 'http://example.com/'); // change the content attribute d
 
      <li>A series of one or more <span>ASCII digits</span>.</li>
 
-     <li>
+     <li>Both of the following, in the given order:
 
       <ol>