Fix typos in wroker message passing

lang/spec.html

@@ -8413,7 +8413,7 @@ <h4 id="receiving_messages">Receiving messages</h4>
 index <var>w</var> of the queue is &gt; <var>i</var>. A value can be
 <em>received from</em> a slot with index <var>i</var> in a queue as follows. If
 the slot is empty, then the receive operation fails; otherwise, the value
-received result the value contained in the slot; in either case, the
+received is the value contained in the slot; in either case, the
 <var>r</var> index in the queue is set to <var>i</var> + 1.
 </p>
 
@@ -8531,8 +8531,8 @@ <h5>Alternate receive action</h5>
 evaluation completes abruptly with a panic, with the associated value being the
 termination value of the sending worker;</li>
 <li>a slot <var>k</var> is ready, and is not empty, and the value in the slot is
-not an error; in this case the alternate-receive-action; in this case, a value
-is received from every slot; the result or failure of these receive operations
+not an error; in this case, a value is received from every slot;
+the result or failure of these receive operations
 is ignored except for slot <var>k</var>; the evaluation completes normally, with
 the result being the value received from slot <var>k</var>; or</li>
 <li>all sending workers have terminated normally; in this case also, a value is