Merge pull request #218 from eyusupov/add-letter

Fix typo

spec/semantics.html

@@ -1181,7 +1181,7 @@ <h2>Constraints for `log:implies`</h2>
 \qquad        &lt;\{\},\{\},\{(\text{:birds},\text{:can}, \text{:fly} )\}&gt; \\
           )\})
         $</div>
-        <div>&ndash; in concrete syntax: <code>{:simon :says {:birds :can :fly}}=>{:bird :can :fly}. </code></div>
+        <div>&ndash; in concrete syntax: <code>{:simon :says {:birds :can :fly}}=>{:birds :can :fly}. </code></div>
 
       <p>Via <a>log-entailment</a> we get:</p>
       <div class="asex">$(\{\},\{\},\{(\text{:birds},\text{:can}, \text{:fly} )\})$</div>