Update shacl12-inf-rules/index.html

Co-authored-by: Ted Thibodeau Jr <[email protected]>

Author: afs

shacl12-inf-rules/index.html

@@ -845,7 +845,8 @@ <h3>Well-formedness Conditions</h3>
               &lt; i</em>.
             </li>
             <li>
-              An [=assignment variable=] is used in only one [=assignment=] in the [=body] of the [=rule=].
+              Each [=assignment variable=] is used in only one [=assignment=] in
+              the [=body] of the [=rule=].
             </li>
             <li>
               An [=assignment variable=] at position <em>i</em> of a [=rule body=] does not