Editorial: correct "is empty" reference

Fixes #329.

encoding.bs

@@ -116,7 +116,7 @@ present in <a for=/>I/O queues</a> of any type and it signifies that there are n
 <a for=/>I/O queue</a> <var>ioQueue</var>, run these steps:
 
 <ol>
- <li><p>If <var>ioQueue</var> is <a for=list>empty</a>, then wait until its <a for=list>size</a> is
+ <li><p>If <var>ioQueue</var> <a for=list>is empty</a>, then wait until its <a for=list>size</a> is
  at least 1.
 
  <li><p>If <var>ioQueue</var>[0] is <a>end-of-queue</a>, then return <a>end-of-queue</a>.
@@ -128,7 +128,7 @@ present in <a for=/>I/O queues</a> of any type and it signifies that there are n
 <var>ioQueue</var>, run these steps:
 
 <ol>
- <li><p>Let <var>readItems</var> be an empty list.
+ <li><p>Let <var>readItems</var> be « ».
 
  <li>
   <p>Perform the following step <var>number</var> times:
@@ -152,7 +152,7 @@ from an <a for=/>I/O queue</a> <var>ioQueue</var>, run these steps:
  <var>number</var>, or <var>ioQueue</var> <a for=list>contains</a> <a>end-of-queue</a>, whichever
  comes first.
 
- <li><p>Let <var>prefix</var> be an empty list.
+ <li><p>Let <var>prefix</var> be « ».
 
  <li>
   <p><a for=list>For each</a> <var>n</var> in <a>the range</a> 1 to <var>number</var>, inclusive: