--- a/ldpatch.html	Sun Dec 14 11:29:26 2014 -0500
+++ b/ldpatch.html	Sun Dec 14 11:33:49 2014 -0500
@@ -534,7 +534,7 @@
         <ul>
             <li>A <dfn>StepForward</dfn> is defined by an IRI, and consists in following the corresponding outgoing arcs in the <a>target graph</a>.</li>
             <li>A <dfn>StepBackward</dfn> is defined by an IRI preceded by the caret ("<code>^</code>") sign, and consists in following the corresponding incoming arcs <em>in reverse</em> in the <a>target graph</a>.</li>
-            <li>A <dfn>StepAt</dfn> is defined by an integer <i>n</i>, and consists in following <var>n</var> <code>rdf:rest</code> arcs and one <code>rdf:first</code> arc in order to reach the corresponding member of an RDF collection. It is equivalent to a sequence of <var>n</var>+1 <a>StepForward</a>s with the corresponding IRIs.</li>
+            <li>A <dfn>StepAt</dfn> is defined by an integer <i>n</i>, and consists in following <var>n</var> <code>rdf:rest</code> arcs and one <code>rdf:first</code> arc in order to reach the corresponding member of an RDF collection. It is equivalent to a sequence of <var>n</var>+1 <a>StepForward</a>s with the corresponding IRIs. A negative index <var>n</var> denotes the n-th element from the end of the list counting backwards.</li>
         </ul>
         <p>
             A <dfn>Constraint</dfn> can be of two kinds: