recursion comments by Peter

shacl/index.html

@@ -1339,6 +1339,19 @@ <h3>Shapes Graph</h3>
 				<p>
 					In addition to shape definitions, the shapes graph may contain additional information for the SHACL processor such as <a href="#entailment">entailment</a> directives.
 				</p>
+				<section id="shapes-recursion">
+					<h4>Shape recursion</h4>
+					<p id="recursion">
+						A <dfn>recursive shape</dfn> is a shape thar refers to itself directly or transitively via
+						<a href="#constraints-shape">shape-based constraint components</a> (i.e. <code>sh:shape</code>),
+						<a href="#constraints-shape">logical constraint components</a> (i.e. <code>sh:or</code>) or
+						<a href="#filterShape">filter shapes</a> (<code>sh:filterShape</code>).
+
+						The handling of recursive shapes is not defined in SHACL and is left to SHACL processor implementations.
+						SHACL processors MAY disallow validation with shapes graph that contain recursive shapes.
+					</p>
+				</section>
+
 			</section>
 
 			<section id="data-graph">
@@ -2836,15 +2849,6 @@ <h4>sh:shape</h4>
 	FILTER (?failure || !?hasShape) .
 }</pre>
 					</div>
-					<p id="recursion">
-						A shape may refer to itself directly or indirectly via <code>sh:shape</code>, <code>sh:filterShape</code>, etc.
-						Such a shape is said to be <em>recursive</em>.
-						The meaning of non-recursive shapes is always well-founded.
-						In contrast, the meaning of a recursive shape may not be well-founded.
-						The handling of recursive shapes in SHACL is left to implementations.
-						Some implementations MAY reject shapes graphs containing recursive shape definitions.
-						Some implementations MAY report a <a>failure</a> if a recursion has been detected at validation time.
-					</p>
 					<p>
 						In the following example, all values of the property <code>ex:someProperty</code> will validate with no results for the shape
 						specified by a blank node that ensures that the property <code>ex:nestedProperty</code> has at least one value.