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Minor edits in the definition of ALP #315

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Minor edits in the definition of ALP #315

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ab035ff
remove unnecessary comment in definition of ALP (addresses #314)
hartig Nov 20, 2025
b0a6719
renames the auxiliary function used in the definition of ALP from ALP…
hartig Nov 20, 2025
dc6d071
'empty set of nodes' --> 'empty set of terms'
hartig Nov 20, 2025
a1f48b3
renames ALP' to ALP_recurse and adapts the anchors accordingly
hartig Nov 28, 2025
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24 changes: 11 additions & 13 deletions spec/index.html
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Original file line number Diff line number Diff line change
Expand Up @@ -9948,7 +9948,7 @@ <h3>Property Path Patterns</h3>
either (<var>yn</var> in <a href="#defn_nodeSet">nodes</a>(<var>G</var>) and <var>xn</var> = <var>yn</var>)
or {(<var>X</var>, <var>xn</var>), (<var>Y</var>, <var>yn</var>)} in ppeval(<var>X</var>, <var>ppe</var>, <var>Y</var>) }</pre>
</div>
<p>We define an auxiliary function, <a href="#defn_evalALP_1">ALP</a>, used in the definitions of <a href="#defn_evalZeroOrMorePath">ZeroOrMorePath</a> and
<p>We define an auxiliary function, <a href="#defn_evalALP">ALP</a>, used in the definitions of <a href="#defn_evalZeroOrMorePath">ZeroOrMorePath</a> and
<a href="#defn_evalOneOrMorePath">OneOrMorePath</a>. Note that the algorithm given here serves to specify the feature. An
implementor is free to implement evaluation by any method that produces the same results
for the query overall. The <a href="#defn_ppeZeroOrMorePath" class="ppeOp">ZeroOrMorePath</a> and <a href="#defn_ppeOneOrMorePath" class="ppeOp">OneOrMorePath</a> forms return matches based on
Expand All @@ -9960,26 +9960,24 @@ <h3>Property Path Patterns</h3>
a node has been visited for the path under consideration, it is not a candidate for another
step.</p>
<div class="defn">
<p><b>Definition: <span id="defn_evalALP_1">Function ALP</span></b></p>
<p><b>Definition: <span id="defn_evalALP">Function ALP</span><span id="defn_evalALP_1"><!-- obsolete id --></span></b></p>
<pre class="nohighlight">
Let <var>ppe</var> be an <a href="#defn_AlgebraicPropertyPathExpression">algebraic property path expression</a>.
Let <span id="defn_reachableTerms"><var>reachableTerms</var></span>(<var>x</var>:term, <var>ppe</var>) be the set of RDF terms
reached by repeated matches of <var>ppe</var>,
when starting at RDF term <var>x</var>.

<a href="#defn_evalALP_1">ALP</a>(<var>x</var>:term, <var>ppe</var>) =
Let <var>V</var> = empty set
<a href="#defn_evalALP_1">ALP</a>(<var>x</var>:term, <var>ppe</var>, <var>V</var>)
<a href="#defn_evalALP">ALP</a>(<var>x</var>:term, <var>ppe</var>) =
Let <var>V</var> = empty set of terms
<a href="#defn_evalALP_recurse">ALP_recurse</a>(<var>x</var>:term, <var>ppe</var>, <var>V</var>)
return is <var>V</var>

# <var>V</var> is the set of nodes visited

<a href="#defn_evalALP_1">ALP</a>(<var>x</var>:term, <var>ppe</var>, <var>V</var>:set of RDF terms) =
<a id="defn_evalALP_recurse" href="#defn_evalALP_recurse">ALP_recurse</a>(<var>x</var>:term, <var>ppe</var>, <var>V</var>:set of RDF terms) =
if ( <var>x</var> in <var>V</var> ) return
add <var>x</var> to <var>V</var>
<var>X</var> = <a href="#defn_reachableTerms"><var>reachableTerms</var></a>(<var>x</var>, <var>ppe</var>)
For <var>n</var>:term in <var>X</var>
<a href="#defn_evalALP_1">ALP</a>(<var>n</var>, <var>ppe</var>, <var>V</var>)
<a href="#defn_evalALP_recurse">ALP_recurse</a>(<var>n</var>, <var>ppe</var>, <var>V</var>)
End
</pre>
</div>
Expand All @@ -9989,7 +9987,7 @@ <h3>Property Path Patterns</h3>
Let <var>G</var> be the <a href="#defn_ActiveGraph">active graph</a>.</p>
<pre class="nohighlight">
ppeval(<var>X</var>:term, <a href="#defn_ppeZeroOrMorePath" class="ppeOp">ZeroOrMorePath</a>(<var>ppe</var>), <var>vy</var>:var) =
{ { (<var>vy</var>, <var>n</var>) } | <var>n</var> in <a href="#defn_evalALP_1">ALP</a>(<var>X</var>, <var>ppe</var>) }
{ { (<var>vy</var>, <var>n</var>) } | <var>n</var> in <a href="#defn_evalALP">ALP</a>(<var>X</var>, <var>ppe</var>) }

ppeval(<var>vx</var>:var, <a href="#defn_ppeZeroOrMorePath" class="ppeOp">ZeroOrMorePath</a>(<var>ppe</var>), <var>vy</var>:var) =
{ { (<var>vx</var>, <var>t</var>), (<var>vy</var>, <var>n</var>) } |
Expand All @@ -10015,7 +10013,7 @@ <h3>Property Path Patterns</h3>
Let <var>X</var> = <a href="#defn_reachableTerms"><var>reachableTerms</var></a>(<var>x</var>, <var>ppe</var>)
Let <var>V</var> = the empty multiset
For <var>n</var> in <var>X</var>
<a href="#defn_evalALP_1">ALP</a>(<var>n</var>, <var>ppe</var>, <var>V</var>)
<a href="#defn_evalALP_recurse">ALP_recurse</a>(<var>n</var>, <var>ppe</var>, <var>V</var>)
End
result is <var>V</var>

Expand Down Expand Up @@ -12727,7 +12725,7 @@ <h2>Changes between SPARQL 1.1 Query Language and SPARQL 1.2 Query Language</h2>
in <a href="#PropertyPathPatterns" class="sectionRef"></a>
from <i>eval</i> to <i>ppeval</i>.</li>
<li>Rename the function used within the definition of
the <a href="#defn_evalALP_1">ALP</a> function
the <a href="#defn_evalALP">ALP</a> function
from <i>eval</i> to <i>reachableTerms</i>.</li>
<li>Add section <a href="#sparql-error" class="sectionRef"></a> about SPARQL expression evaluation errors</a>.</li>
<li>Rename section "Filter evaluation" as <a href="#expression-evaluation" class="sectionRef"></a>.</li>
Expand All @@ -12745,7 +12743,7 @@ <h2>Changes between SPARQL 1.1 Query Language and SPARQL 1.2 Query Language</h2>
<li><a href="https://www.w3.org/2013/sparql-errata#clarification-query-1">clarification-query-1</a>: Fix explanation of IN and NOT IN in <a href="#func-in" class="sectionRef"></a> and <a href="#func-not-in" class="sectionRef"></a></li>
<li><a href="https://www.w3.org/2013/sparql-errata#clarification-query-2">clarification-query-2</a>: Remove unneeded reference to the semantics above in <a href="#operatorExtensibility" class="sectionRef"></a></li>
<li><a href="https://www.w3.org/2013/sparql-errata#clarification-query-3">clarification-query-3</a>: Rephrase equality definition in <a href="#func-sameValue" class="sectionRef"></a></li>
<li><a href="https://www.w3.org/2013/sparql-errata#errata-query-1">errata-query-1</a>: Let V be an empty set instead of empty multiset in <a href="#defn_evalALP_1">Function ALP definition</a></li>
<li><a href="https://www.w3.org/2013/sparql-errata#errata-query-1">errata-query-1</a>: Let V be an empty set instead of empty multiset in <a href="#defn_evalALP">Function ALP definition</a></li>
<li><a href="https://www.w3.org/2013/sparql-errata#errata-query-2">errata-query-2</a>: Fix grammar of PropertyListPathNotEmpty in <a href="#grammar" class="sectionRef"></a></li>
<li><a href="https://www.w3.org/2013/sparql-errata#errata-query-4">errata-query-4</a>: Fix CONCAT definition for zero and one argument in <a href="#func-concat" class="sectionRef"></a></li>
<li><a href="https://www.w3.org/2013/sparql-errata#errata-query-5">errata-query-5</a>: Mention illegal nesting of aggregates in <a href="#sparqlGrammar" class="sectionRef"></a></li>
Expand Down
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