diff --git a/CHANGELOG.md b/CHANGELOG.md
index 3d08644..1cdb5e1 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -14,7 +14,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Added
 
-- Conformance corpus harness (#105, Tier 2): the start of conformance-suite checking, expressed through the validation framework (the OpenAPIKit idiom). A `PureXML.Validation.ConformanceCase` is a `Validatable` named expectation (actual vs spec-authoritative expected output), and `Conformance.matchesExpected` is a `Validation<ConformanceCase, Void>` rule that emits one located `ValidationError` per diverging case, so a whole suite reports every failure at once with the case name as its coding path. Seeded with a Canonical XML 1.0 corpus (attribute ordering, empty-element expansion, comment removal, CDATA-to-escaped-text, processing instructions, namespace rendering). Growing the corpora against the official W3C/OASIS suites is the ongoing Tier-2 work.
+- Conformance corpus harness (#105, Tier 2): the start of conformance-suite checking, expressed through the validation framework (the OpenAPIKit idiom). A `PureXML.Validation.ConformanceCase` is a `Validatable` named expectation (actual vs spec-authoritative expected output), and `Conformance.matchesExpected` is a `Validation<ConformanceCase, Void>` rule that emits one located `ValidationError` per diverging case, so a whole suite reports every failure at once with the case name as its coding path. Seeded with a Canonical XML 1.0 corpus (attribute ordering, empty-element expansion, comment removal, CDATA-to-escaped-text, processing instructions, namespace rendering) and an XPath 1.0 core-function corpus (the string, number, boolean, and node functions against their spec-mandated results, including the `Infinity`/`NaN` division cases). Growing the corpora against the official W3C/OASIS suites is the ongoing Tier-2 work.
 - EXSLT extension functions (#105, Tier 3): the `common`, `math`, and `sets` EXSLT modules, dispatched by resolving a function's prefix to its namespace (so any prefix bound to an EXSLT namespace works). `math:min`, `math:max`, `math:highest`, `math:lowest`, `math:abs`, `math:sqrt` (with the EXSLT NaN rule for non-numeric nodes); `set:distinct`, `set:difference`, `set:intersection`, `set:has-same-node`, `set:leading`, `set:trailing` (by node identity and document order); `exsl:object-type`. `math:power` and the other transcendentals are omitted because they need a C math library, which the pure-Swift, Foundation-free target excludes; `exsl:node-set` awaits result-tree-fragment support.
 - Canonical XML 1.1 (#105, Tier 3): a `Canonical.Options.canonical11` preset and a `mergeInheritedBase` option. When canonicalizing a document subset, the `xml:base` values of the apex's omitted ancestors are merged into the apex by RFC 3986 reference resolution (vs. 1.0's nearest-ancestor rule), the apex's own relative `xml:base` is resolved against that chain, and `xml:id` is no longer inherited; `xml:lang` and `xml:space` still inherit the nearest. A self-contained RFC 3986 resolver (scheme/authority/path parsing, path merging, dot-segment removal) backs the merge.
 - Single-byte legacy encodings (#97): the byte decoder gains a table-based single-byte path and the full set of single-byte legacy encodings, selected by the XML declaration's `encoding` name for both the whole-buffer and streaming decoders: the complete ISO-8859 family (parts 2 through 16), Windows-1250/1251/1253/1254/1255/1256/1257/1258, and KOI8-R/U. Most are vendored verbatim from the authoritative `unicode.org` mapping files; ISO-8859-5/9/15 are derived exactly; Windows-1254 composes from Windows-1252. Multi-byte CJK encodings (#99) are tracked separately.
diff --git a/README.md b/README.md
index 18e7d58..dc9dca9 100644
--- a/README.md
+++ b/README.md
@@ -99,7 +99,7 @@ flowchart TB
 
 PureXML is a working, dependency-free XML library today: parse, emit, validate,
 query, and stream documents on macOS, Linux, Windows, and WASM. The test suite
-currently runs **809 tests in 125 suites** (`swift test`).
+currently runs **810 tests in 125 suites** (`swift test`).
 
 ### Shipped (libxml2-aligned surface)
 
diff --git a/Tests/ConformanceCorpusTests.swift b/Tests/ConformanceCorpusTests.swift
index 5cdda1c..d0120f8 100644
--- a/Tests/ConformanceCorpusTests.swift
+++ b/Tests/ConformanceCorpusTests.swift
@@ -29,12 +29,52 @@ struct ConformanceCorpusTests {
         }
     }
 
+    private struct XPathSpec {
+        let name: String
+        let expression: String
+        let expected: String
+    }
+
+    /// XPath 1.0 core-function conformance points: the function's result coerced
+    /// to a string, against the value the specification mandates.
+    private func xpathCorpus() throws -> [PureXML.Validation.ConformanceCase] {
+        let document = try PureXML.parse("<r><item/><item/><item/></r>")
+        let specs = [
+            XPathSpec(name: "concat", expression: "concat('a','b','c')", expected: "abc"),
+            XPathSpec(name: "substring-length", expression: "substring('12345',2,3)", expected: "234"),
+            XPathSpec(name: "substring-open", expression: "substring('12345',2)", expected: "2345"),
+            XPathSpec(name: "string-length", expression: "string-length('hello')", expected: "5"),
+            XPathSpec(name: "normalize-space", expression: "normalize-space('  a  b  ')", expected: "a b"),
+            XPathSpec(name: "translate", expression: "translate('bar','abc','ABC')", expected: "BAr"),
+            XPathSpec(name: "substring-before", expression: "substring-before('a/b','/')", expected: "a"),
+            XPathSpec(name: "substring-after", expression: "substring-after('a/b','/')", expected: "b"),
+            XPathSpec(name: "contains", expression: "contains('hello','ell')", expected: "true"),
+            XPathSpec(name: "starts-with", expression: "starts-with('hello','he')", expected: "true"),
+            XPathSpec(name: "round-half-up", expression: "round(2.5)", expected: "3"),
+            XPathSpec(name: "floor", expression: "floor(2.9)", expected: "2"),
+            XPathSpec(name: "ceiling", expression: "ceiling(2.1)", expected: "3"),
+            XPathSpec(name: "count", expression: "count(//item)", expected: "3"),
+            XPathSpec(name: "div-by-zero-infinity", expression: "1 div 0", expected: "Infinity"),
+            XPathSpec(name: "zero-div-zero-nan", expression: "0 div 0", expected: "NaN"),
+        ]
+        return try specs.map { spec in
+            let actual = try PureXML.XPath.Query(spec.expression).string(over: document)
+            return PureXML.Validation.ConformanceCase(name: spec.name, actual: actual, expected: spec.expected)
+        }
+    }
+
     @Test("The C14N conformance corpus passes with no located failures")
     func test_corpusConforms() throws {
         let failures = try PureXML.Validation.Conformance.failures(in: canonicalCorpus())
         #expect(failures.isEmpty, "\(failures.map(\.reason))")
     }
 
+    @Test("The XPath core-function conformance corpus passes with no located failures")
+    func test_xpathCorpusConforms() throws {
+        let failures = try PureXML.Validation.Conformance.failures(in: xpathCorpus())
+        #expect(failures.isEmpty, "\(failures.map(\.reason))")
+    }
+
     @Test("A divergent case is reported as a located conformance failure")
     func test_divergenceReported() {
         let bad = PureXML.Validation.ConformanceCase(name: "wrong", actual: "<a></a>", expected: "<b></b>")