diff --git a/pmd-apex/src/main/resources/category/apex/codestyle.xml b/pmd-apex/src/main/resources/category/apex/codestyle.xml
index 262b6f9757..72c22c83ce 100644
--- a/pmd-apex/src/main/resources/category/apex/codestyle.xml
+++ b/pmd-apex/src/main/resources/category/apex/codestyle.xml
@@ -48,9 +48,9 @@ from the rest.
             <property name="xpath">
                 <value>
 <![CDATA[
-//IfBlockStatement/BlockStatement[@CurlyBrace='false'][count(child::*) > 0]
+//IfBlockStatement/BlockStatement[@CurlyBrace= false()][count(child::*) > 0]
 |
-//IfElseBlockStatement/BlockStatement[@CurlyBrace='false'][count(child::*) > 0]
+//IfElseBlockStatement/BlockStatement[@CurlyBrace= false()][count(child::*) > 0]
 ]]>
                 </value>
             </property>
@@ -85,7 +85,7 @@ controlled from the rest.
             <property name="xpath">
                 <value>
 <![CDATA[
-//IfBlockStatement/BlockStatement[@CurlyBrace='false']
+//IfBlockStatement/BlockStatement[@CurlyBrace= false()]
 ]]>
                 </value>
             </property>
@@ -142,9 +142,9 @@ from the rest.
             <property name="xpath">
                 <value>
 <![CDATA[
-//ForLoopStatement/BlockStatement[@CurlyBrace='false']
+//ForLoopStatement/BlockStatement[@CurlyBrace= false()]
 |
-//ForEachStatement/BlockStatement[@CurlyBrace='false']
+//ForEachStatement/BlockStatement[@CurlyBrace= false()]
 ]]>
                 </value>
             </property>
@@ -348,7 +348,7 @@ controlled from the rest.
             <property name="xpath">
                 <value>
 <![CDATA[
-//WhileLoopStatement/BlockStatement[@CurlyBrace='false']
+//WhileLoopStatement/BlockStatement[@CurlyBrace= false()]
 ]]>
                 </value>
             </property>
diff --git a/pmd-apex/src/main/resources/category/apex/errorprone.xml b/pmd-apex/src/main/resources/category/apex/errorprone.xml
index c96110f960..17c9182938 100644
--- a/pmd-apex/src/main/resources/category/apex/errorprone.xml
+++ b/pmd-apex/src/main/resources/category/apex/errorprone.xml
@@ -189,7 +189,7 @@ Empty block statements serve no purpose and should be removed.
             <property name="xpath">
                 <value>
 <![CDATA[
-//Method/ModifierNode[@Abstract!='true' and ../BlockStatement[count(*) = 0]]
+//Method/ModifierNode[@Abstract!= true() and ../BlockStatement[count(*) = 0]]
 | //Method/BlockStatement//BlockStatement[count(*) = 0 and @Location != parent::*/@Location]
 ]]>
                 </value>
diff --git a/pmd-core/src/main/java/net/sourceforge/pmd/lang/ast/xpath/saxon/ElementNode.java b/pmd-core/src/main/java/net/sourceforge/pmd/lang/ast/xpath/saxon/ElementNode.java
index 4663e7f1bf..94bec1fbb1 100644
--- a/pmd-core/src/main/java/net/sourceforge/pmd/lang/ast/xpath/saxon/ElementNode.java
+++ b/pmd-core/src/main/java/net/sourceforge/pmd/lang/ast/xpath/saxon/ElementNode.java
@@ -122,6 +122,13 @@ public class ElementNode extends AbstractNodeInfo {
         return result;
     }
 
+
+    @Override
+    public String getDisplayName() {
+        return getLocalPart();
+    }
+
+
     @SuppressWarnings("PMD.MissingBreakInSwitch")
     @Override
     public AxisIterator iterateAxis(byte axisNumber) {
diff --git a/pmd-core/src/main/java/net/sourceforge/pmd/lang/rule/XPathRule.java b/pmd-core/src/main/java/net/sourceforge/pmd/lang/rule/XPathRule.java
index 773d64a5c0..55257976f9 100644
--- a/pmd-core/src/main/java/net/sourceforge/pmd/lang/rule/XPathRule.java
+++ b/pmd-core/src/main/java/net/sourceforge/pmd/lang/rule/XPathRule.java
@@ -41,8 +41,8 @@ public class XPathRule extends AbstractRule {
 
     static {
         Map<String, String> tmp = new HashMap<>();
-        tmp.put(XPATH_1_0, XPATH_1_0);
-        tmp.put(XPATH_1_0_COMPATIBILITY, XPATH_1_0_COMPATIBILITY);
+        tmp.put(XPATH_1_0, XPATH_2_0);
+        tmp.put(XPATH_1_0_COMPATIBILITY, XPATH_2_0);
         tmp.put(XPATH_2_0, XPATH_2_0);
         XPATH_VERSIONS = Collections.unmodifiableMap(tmp);
     }
@@ -51,7 +51,7 @@ public class XPathRule extends AbstractRule {
     public static final EnumeratedProperty<String> VERSION_DESCRIPTOR = EnumeratedProperty.<String>named("version")
             .desc("XPath specification version")
             .mappings(XPATH_VERSIONS)
-            .defaultValue(XPATH_1_0)
+            .defaultValue(XPATH_2_0)
             .type(String.class)
             .uiOrder(2.0f)
             .build();
diff --git a/pmd-core/src/test/resources/net/sourceforge/pmd/xml/j2ee.xml b/pmd-core/src/test/resources/net/sourceforge/pmd/xml/j2ee.xml
index f158927f95..607967f6fd 100644
--- a/pmd-core/src/test/resources/net/sourceforge/pmd/xml/j2ee.xml
+++ b/pmd-core/src/test/resources/net/sourceforge/pmd/xml/j2ee.xml
@@ -324,9 +324,9 @@ behavior especially when instances are distributed by the container on several J
     )
     and
     (./ClassOrInterfaceBody/ClassOrInterfaceBodyDeclaration[
-         (./FieldDeclaration[@Static = 'true'])
+         (./FieldDeclaration[@Static = true()])
          and
-         (./FieldDeclaration[@Final = 'false'])
+         (./FieldDeclaration[@Final = false()])
     ])
 ]
     		 ]]></value>
diff --git a/pmd-java/src/main/resources/category/java/bestpractices.xml b/pmd-java/src/main/resources/category/java/bestpractices.xml
index 5c089e46d7..7dd321aee1 100644
--- a/pmd-java/src/main/resources/category/java/bestpractices.xml
+++ b/pmd-java/src/main/resources/category/java/bestpractices.xml
@@ -27,8 +27,8 @@ directly) a protected constructor can be provided prevent direct instantiation.
                 <value>
 <![CDATA[
 //ClassOrInterfaceDeclaration
- [@Abstract='true'
-  and count( .//MethodDeclaration[@Abstract='true'] )=0 ]
+ [@Abstract= true()
+  and count( .//MethodDeclaration[@Abstract= true()] )=0 ]
   [count(ImplementsList)=0]
   [count(.//ExtendsList)=0]
 ]]>
@@ -380,7 +380,7 @@ better placed in classes or enums. See Effective Java, item 19.
             <property name="xpath">
                 <value>
 <![CDATA[
-//ClassOrInterfaceDeclaration[@Interface='true'][$ignoreIfHasMethods='false' or not(.//MethodDeclaration)]//FieldDeclaration
+//ClassOrInterfaceDeclaration[@Interface= true()][$ignoreIfHasMethods= false() or not(.//MethodDeclaration)]//FieldDeclaration
  ]]>
                 </value>
             </property>
@@ -426,8 +426,8 @@ By convention, the default label should be the last label in a switch statement.
                 <value>
 <![CDATA[
 //SwitchStatement
- [not(SwitchLabel[position() = last()][@Default='true'])]
- [SwitchLabel[@Default='true']]
+ [not(SwitchLabel[position() = last()][@Default= true()])]
+ [SwitchLabel[@Default= true()]]
 ]]>
                 </value>
             </property>
@@ -1075,7 +1075,7 @@ can be avoided, they will just return false.
 //PrimaryExpression[
     PrimaryPrefix[Name[(ends-with(@Image, '.equals'))]]
         [
-            (../PrimarySuffix/Arguments/ArgumentList/Expression/PrimaryExpression/PrimaryPrefix/Literal[@StringLiteral='true'])
+            (../PrimarySuffix/Arguments/ArgumentList/Expression/PrimaryExpression/PrimaryPrefix/Literal[@StringLiteral= true()])
             and
             ( count(../PrimarySuffix/Arguments/ArgumentList/Expression) = 1 )
         ]
diff --git a/pmd-java/src/main/resources/category/java/codestyle.xml b/pmd-java/src/main/resources/category/java/codestyle.xml
index 6f8e3e2ae4..1cb7beabeb 100644
--- a/pmd-java/src/main/resources/category/java/codestyle.xml
+++ b/pmd-java/src/main/resources/category/java/codestyle.xml
@@ -28,12 +28,12 @@ by {% rule java/codestyle/ClassNamingConventions %}.
                 <value>
 <![CDATA[
 //ClassOrInterfaceDeclaration
- [@Abstract='true' and @Interface='false']
+ [@Abstract= true() and @Interface= false()]
  [not (starts-with(@SimpleName,'Abstract'))]
 |
 //ClassOrInterfaceDeclaration
- [@Abstract='false']
- [$strict='true']
+ [@Abstract= false()]
+ [$strict= true()]
  [starts-with(@SimpleName, 'Abstract')]
 ]]>
                 </value>
@@ -116,7 +116,7 @@ If the goal is to avoid defining constants in a scope smaller than the class, th
                 <value>
 <![CDATA[
 //LocalVariableDeclaration[
-  @Final = 'true'
+  @Final = true()
   and not(../../ForStatement)
   and
   (
@@ -213,9 +213,9 @@ Clarify your intent by using private or package access modifiers instead.
             <property name="xpath">
                 <value>
 <![CDATA[
-//ClassOrInterfaceDeclaration[@Final='true']
+//ClassOrInterfaceDeclaration[@Final= true()]
 /ClassOrInterfaceBody/ClassOrInterfaceBodyDeclaration
-/FieldDeclaration[@Protected='true']
+/FieldDeclaration[@Protected= true()]
 ]]>
                 </value>
             </property>
@@ -244,12 +244,13 @@ visibility cannot be reduced). Clarify your intent by using private or package a
         </description>
         <priority>3</priority>
         <properties>
+            <property name="version" value="2.0"/>
             <property name="xpath">
                 <value>
 <![CDATA[
-//ClassOrInterfaceDeclaration[@Final='true' and not(ExtendsList)]
+//ClassOrInterfaceDeclaration[@Final= true() and not(ExtendsList)]
 /ClassOrInterfaceBody/ClassOrInterfaceBodyDeclaration
-/MethodDeclaration[@Protected='true' and @Name != 'finalize']
+/MethodDeclaration[@Protected=true() and @Name != 'finalize']
  ]]>
                 </value>
             </property>
@@ -318,7 +319,7 @@ prefix for these methods.
 <![CDATA[
 //MethodDeclaration
     [starts-with(@Name, 'get')]
-    [@Arity = 0 or $checkParameterizedMethods = 'true']
+    [@Arity = 0 or $checkParameterizedMethods = true()]
     [
         ResultType/Type/PrimitiveType[@Image = 'boolean']
         and not(../Annotation//Name[@Image = 'Override'])
@@ -552,13 +553,13 @@ The rule allows methods and fields annotated with Guava's @VisibleForTesting.
             <property name="xpath">
                 <value>
 <![CDATA[
-//ClassOrInterfaceDeclaration[@Interface='false']
+//ClassOrInterfaceDeclaration[@Interface= false()]
 /ClassOrInterfaceBody
 /ClassOrInterfaceBodyDeclaration
 [not(Annotation//Name[ends-with(@Image, 'VisibleForTesting')])]
 [
-FieldDeclaration[@PackagePrivate='true']
-or MethodDeclaration[@PackagePrivate='true']
+FieldDeclaration[@PackagePrivate= true()]
+or MethodDeclaration[@PackagePrivate= true()]
 ]
 ]]>
                 </value>
@@ -623,16 +624,16 @@ usage by developers who should be implementing their own versions in the concret
             <property name="xpath">
                 <value>
 <![CDATA[
-//ClassOrInterfaceDeclaration[@Abstract = 'true']
+//ClassOrInterfaceDeclaration[@Abstract = true()]
     /ClassOrInterfaceBody
     /ClassOrInterfaceBodyDeclaration
-    /MethodDeclaration[@Abstract = 'false' and @Native = 'false']
+    /MethodDeclaration[@Abstract = false() and @Native = false()]
     [
-        ( boolean(./Block[count(./BlockStatement) =  1]/BlockStatement/Statement/ReturnStatement/Expression/PrimaryExpression/PrimaryPrefix/Literal/NullLiteral) = 'true' )
+        ( boolean(./Block[count(./BlockStatement) =  1]/BlockStatement/Statement/ReturnStatement/Expression/PrimaryExpression/PrimaryPrefix/Literal/NullLiteral) = true() )
         or
-        ( boolean(./Block[count(./BlockStatement) =  1]/BlockStatement/Statement/ReturnStatement/Expression/PrimaryExpression/PrimaryPrefix/Literal[@Image = '0']) = 'true' )
+        ( boolean(./Block[count(./BlockStatement) =  1]/BlockStatement/Statement/ReturnStatement/Expression/PrimaryExpression/PrimaryPrefix/Literal[@Image = '0']) = true() )
         or
-        ( boolean(./Block[count(./BlockStatement) =  1]/BlockStatement/Statement/ReturnStatement/Expression/PrimaryExpression/PrimaryPrefix/Literal[string-length(@Image) = 2]) = 'true' )
+        ( boolean(./Block[count(./BlockStatement) =  1]/BlockStatement/Statement/ReturnStatement/Expression/PrimaryExpression/PrimaryPrefix/Literal[string-length(@Image) = 2]) = true() )
         or
         (./Block[count(./BlockStatement) =  1]/BlockStatement/Statement/EmptyStatement)
         or
@@ -866,7 +867,7 @@ Names for references to generic values should be limited to a single uppercase l
 //TypeDeclaration/ClassOrInterfaceDeclaration/TypeParameters/TypeParameter[
   string-length(@Image) > 1
   or
-  string:upper-case(@Image) != @Image
+  upper-case(@Image) != @Image
 ]
 ]]>
                 </value>
@@ -947,7 +948,7 @@ by the rule {% rule java/codestyle/ControlStatementBraces %}.
                 <value>
 <![CDATA[
 //Statement
- [parent::IfStatement[@Else='true']]
+ [parent::IfStatement[@Else= true()]]
  [not(child::Block)]
  [not(child::IfStatement)]
 ]]>
@@ -1728,9 +1729,9 @@ by the more general rule {% rule java/codestyle/FieldNamingConventions %}.
             <property name="xpath">
                 <value>
 <![CDATA[
-//ClassOrInterfaceDeclaration[@Interface='false']
+//ClassOrInterfaceDeclaration[@Interface= false()]
  /ClassOrInterfaceBody/ClassOrInterfaceBodyDeclaration/FieldDeclaration
-  [@Final='false']
+  [@Final= false()]
   [VariableDeclarator/VariableDeclaratorId[upper-case(@Image)=@Image]]
 ]]>
                 </value>
@@ -1767,7 +1768,7 @@ which class a static member comes from (Sun 1.5 Language Guide).
             <property name="xpath">
                 <value>
 <![CDATA[
-.[count(ImportDeclaration[@Static = 'true']) > $maximumStaticImports]
+.[count(ImportDeclaration[@Static = true()]) > $maximumStaticImports]
 ]]>
                 </value>
             </property>
@@ -1970,15 +1971,15 @@ which makes the code also more readable.
             <property name="xpath">
                 <value>
                     <![CDATA[
-//VariableInitializer[preceding-sibling::VariableDeclaratorId[1]/@TypeInferred="false"]
+//VariableInitializer[preceding-sibling::VariableDeclaratorId[1]/@TypeInferred=false()]
 //PrimaryExpression[not(PrimarySuffix)]
 [not(ancestor::ArgumentList)]
-/PrimaryPrefix/AllocationExpression[ClassOrInterfaceType[@AnonymousClass='false']/TypeArguments//ReferenceType[not(.//TypeArguments)]]
+/PrimaryPrefix/AllocationExpression[ClassOrInterfaceType[@AnonymousClass= false()]/TypeArguments//ReferenceType[not(.//TypeArguments)]]
 |
 //StatementExpression[AssignmentOperator][PrimaryExpression/PrimaryPrefix[not(Expression)]]
 //PrimaryExpression[not(PrimarySuffix)]
 [not(ancestor::ArgumentList)]
-/PrimaryPrefix/AllocationExpression[ClassOrInterfaceType[@AnonymousClass='false']/TypeArguments//ReferenceType[not(.//TypeArguments)]]
+/PrimaryPrefix/AllocationExpression[ClassOrInterfaceType[@AnonymousClass= false()]/TypeArguments//ReferenceType[not(.//TypeArguments)]]
 ]]>
                 </value>
             </property>
@@ -2031,7 +2032,7 @@ List<String> stringsWithDiamond = new ArrayList<>(); // using the diamond operat
     not(./CastExpression) and
     not(./EqualityExpression)]
 |
-//Expression/AdditiveExpression[not(./PrimaryExpression/PrimaryPrefix/Literal[@StringLiteral='true'])]
+//Expression/AdditiveExpression[not(./PrimaryExpression/PrimaryPrefix/Literal[@StringLiteral= true()])]
   /PrimaryExpression[1]/PrimaryPrefix/Expression[
     count(*)=1 and
     not(./CastExpression) and
@@ -2093,9 +2094,9 @@ public class Foo {
 <![CDATA[
 //PrimaryExpression
 [PrimaryPrefix/Name[@Image]]
-[PrimarySuffix[@Arguments='false' and @ArrayDereference = 'false']]
+[PrimarySuffix[@Arguments= false() and @ArrayDereference = false()]]
 [not(PrimarySuffix/MemberSelector)]
-[ancestor::ClassOrInterfaceBodyDeclaration[1][@AnonymousInnerClass='false']]
+[ancestor::ClassOrInterfaceBodyDeclaration[1][@AnonymousInnerClass= false()]]
 /PrimaryPrefix/Name[@Image = ancestor::ClassOrInterfaceDeclaration[1]/@SimpleName]
 ]]>
                 </value>
diff --git a/pmd-java/src/main/resources/category/java/design.xml b/pmd-java/src/main/resources/category/java/design.xml
index 73008d3e30..4a3dfa92dc 100644
--- a/pmd-java/src/main/resources/category/java/design.xml
+++ b/pmd-java/src/main/resources/category/java/design.xml
@@ -27,7 +27,7 @@ protected constructor in order to prevent instantiation than make the class misl
                 <value>
 <![CDATA[
 //ClassOrInterfaceDeclaration
-    [@Abstract = 'true']
+    [@Abstract = true()]
     [count(//MethodDeclaration) + count(//ConstructorDeclaration) = 0]
     [not(../Annotation/MarkerAnnotation/Name[pmd-java:typeIs('com.google.auto.value.AutoValue')])]
 ]]>
@@ -339,9 +339,9 @@ is invoked by a inner class.
                 <value>
 <![CDATA[
 TypeDeclaration[count(../TypeDeclaration) = 1]/ClassOrInterfaceDeclaration
-[@Final = 'false']
-[count(./ClassOrInterfaceBody/ClassOrInterfaceBodyDeclaration/ConstructorDeclaration[@Private = 'true']) >= 1 ]
-[count(./ClassOrInterfaceBody/ClassOrInterfaceBodyDeclaration/ConstructorDeclaration[(@Public = 'true') or (@Protected = 'true') or (@PackagePrivate = 'true')]) = 0 ]
+[@Final = false()]
+[count(./ClassOrInterfaceBody/ClassOrInterfaceBodyDeclaration/ConstructorDeclaration[@Private = true()]) >= 1 ]
+[count(./ClassOrInterfaceBody/ClassOrInterfaceBodyDeclaration/ConstructorDeclaration[(@Public = true()) or (@Protected = true()) or (@PackagePrivate = true())]) = 0 ]
 [not(.//ClassOrInterfaceDeclaration)]
 ]]>
                 </value>
@@ -370,12 +370,12 @@ Sometimes two consecutive 'if' statements can be consolidated by separating thei
             <property name="xpath">
                 <value>
 <![CDATA[
-//IfStatement[@Else='false']/Statement
- /IfStatement[@Else='false']
+//IfStatement[@Else= false()]/Statement
+ /IfStatement[@Else= false()]
  |
-//IfStatement[@Else='false']/Statement
+//IfStatement[@Else= false()]/Statement
  /Block[count(BlockStatement)=1]/BlockStatement
-  /Statement/IfStatement[@Else='false']
+  /Statement/IfStatement[@Else= false()]
 ]]>
                 </value>
             </property>
@@ -727,7 +727,7 @@ in each object at runtime.
                 <value>
 <![CDATA[
 //FieldDeclaration
- [@Final='true' and @Static='false']
+ [@Final= true() and @Static= false()]
    /VariableDeclarator/VariableInitializer/Expression
     /PrimaryExpression[not(PrimarySuffix)]/PrimaryPrefix/Literal
 ]]>
@@ -1373,7 +1373,7 @@ ConditionalAndExpression
  [EqualityExpression[@Image='!=']//NullLiteral
  and
 InstanceOfExpression
- [PrimaryExpression[count(PrimarySuffix[@ArrayDereference='true'])=0]
+ [PrimaryExpression[count(PrimarySuffix[@ArrayDereference= true()])=0]
   //Name[not(contains(@Image,'.'))]/@Image = ancestor::ConditionalAndExpression
    /EqualityExpression/PrimaryExpression/PrimaryPrefix/Name/@Image]
  and
diff --git a/pmd-java/src/main/resources/category/java/documentation.xml b/pmd-java/src/main/resources/category/java/documentation.xml
index 7b6d5cd81f..daee1d547d 100644
--- a/pmd-java/src/main/resources/category/java/documentation.xml
+++ b/pmd-java/src/main/resources/category/java/documentation.xml
@@ -94,8 +94,8 @@ and unintentional empty constructors.
             <property name="xpath">
                 <value>
 <![CDATA[
-//ConstructorDeclaration[@Private='false']
-                        [count(BlockStatement) = 0 and ($ignoreExplicitConstructorInvocation = 'true' or not(ExplicitConstructorInvocation)) and @containsComment = 'false']
+//ConstructorDeclaration[@Private= false()]
+                        [count(BlockStatement) = 0 and ($ignoreExplicitConstructorInvocation = true() or not(ExplicitConstructorInvocation)) and @containsComment = false()]
                         [not(../Annotation/MarkerAnnotation/Name[pmd-java:typeIs('javax.inject.Inject')])]
 ]]>
                 </value>
@@ -128,7 +128,7 @@ empty methods.
             <property name="xpath">
                 <value>
 <![CDATA[
-//MethodDeclaration/Block[count(BlockStatement) = 0 and @containsComment = 'false']
+//MethodDeclaration/Block[count(BlockStatement) = 0 and @containsComment = false()]
 ]]>
                 </value>
             </property>
diff --git a/pmd-java/src/main/resources/category/java/errorprone.xml b/pmd-java/src/main/resources/category/java/errorprone.xml
index 938ca51d55..3415522b1e 100644
--- a/pmd-java/src/main/resources/category/java/errorprone.xml
+++ b/pmd-java/src/main/resources/category/java/errorprone.xml
@@ -734,7 +734,7 @@ public String bar(String string) {
   @Name='onStart'
   ]
     /Block[not(
-      (BlockStatement[1]/Statement/StatementExpression/PrimaryExpression[./PrimaryPrefix[@SuperModifier='true']]/PrimarySuffix[@Image= ancestor::MethodDeclaration/@Name]))]
+      (BlockStatement[1]/Statement/StatementExpression/PrimaryExpression[./PrimaryPrefix[@SuperModifier= true()]]/PrimarySuffix[@Image= ancestor::MethodDeclaration/@Name]))]
 [ancestor::ClassOrInterfaceDeclaration[ExtendsList/ClassOrInterfaceType[
   pmd-java:typeIs('android.app.Activity') or
   pmd-java:typeIs('android.app.Application') or
@@ -779,7 +779,7 @@ Super should be called at the end of the method
   @Name='onTerminate'
   ]
    /Block/BlockStatement[last()]
-    [not(Statement/StatementExpression/PrimaryExpression[./PrimaryPrefix[@SuperModifier='true']]/PrimarySuffix[@Image= ancestor::MethodDeclaration/@Name])]
+    [not(Statement/StatementExpression/PrimaryExpression[./PrimaryPrefix[@SuperModifier= true()]]/PrimarySuffix[@Image= ancestor::MethodDeclaration/@Name])]
 [ancestor::ClassOrInterfaceDeclaration[ExtendsList/ClassOrInterfaceType[
   pmd-java:typeIs('android.app.Activity') or
   pmd-java:typeIs('android.app.Application') or
@@ -892,7 +892,7 @@ Object.clone (which is protected) with a public method."
             <property name="xpath">
                 <value>
 <![CDATA[
-//MethodDeclaration[@Public='false']
+//MethodDeclaration[@Public= false()]
   [@Name = 'clone']
   [@Arity = 0]
 ]]>
@@ -1013,7 +1013,7 @@ and count(NameList/Name[contains
 (@Image,'CloneNotSupportedException')]) = 0
 ]
 [
-../../../../ClassOrInterfaceDeclaration[@Final = 'false']
+../../../../ClassOrInterfaceDeclaration[@Final = false()]
 ]
 ]]>
                 </value>
@@ -1474,7 +1474,7 @@ or reported.
                 <value>
 <![CDATA[
 //CatchStatement
- [count(Block/BlockStatement) = 0 and ($allowCommentedBlocks != 'true' or Block/@containsComment = 'false')]
+ [count(Block/BlockStatement) = 0 and ($allowCommentedBlocks != true() or Block/@containsComment = false())]
  [FormalParameter/Type/ReferenceType
    /ClassOrInterfaceType[@Image != 'InterruptedException' and @Image != 'CloneNotSupportedException']
  ]
@@ -1882,13 +1882,13 @@ a block whose last statement is NOT a call to super.finalize -->
    /Block
       /BlockStatement[last()]
       [not(Statement/StatementExpression/PrimaryExpression
-            [./PrimaryPrefix[@SuperModifier='true']]
+            [./PrimaryPrefix[@SuperModifier= true()]]
             [./PrimarySuffix[@Image='finalize']]
           )
       ]
       [not(Statement/TryStatement/FinallyStatement
        /Block/BlockStatement/Statement/StatementExpression/PrimaryExpression
-            [./PrimaryPrefix[@SuperModifier='true']]
+            [./PrimaryPrefix[@SuperModifier= true()]]
             [./PrimarySuffix[@Image='finalize']]
           )
       ]
@@ -1924,7 +1924,7 @@ If the finalize() is implemented, it should do something besides just calling su
    /Block[count(BlockStatement)=1]
      /BlockStatement[
        Statement/StatementExpression/PrimaryExpression
-       [./PrimaryPrefix[@SuperModifier='true']]
+       [./PrimaryPrefix[@SuperModifier= true()]]
        [./PrimarySuffix[@Image='finalize']]
      ]
 ]]>
@@ -1990,7 +1990,7 @@ Note that Oracle has declared Object.finalize() as deprecated since JDK 9.
             <property name="xpath">
                 <value>
 <![CDATA[
-//MethodDeclaration[@Protected="false"][@Name='finalize'][@Arity = 0]
+//MethodDeclaration[@Protected=false()][@Name='finalize'][@Arity = 0]
 ]]>
                 </value>
             </property>
@@ -2199,7 +2199,7 @@ The suite() method in a JUnit test needs to be both public and static.
             <property name="xpath">
                 <value>
 <![CDATA[
-//MethodDeclaration[not(@Static='true') or not(@Public='true')]
+//MethodDeclaration[not(@Static= true()) or not(@Public= true())]
 [@Name='suite']
 [@Arity = 0]
 [ancestor::ClassOrInterfaceDeclaration[//ClassOrInterfaceType[pmd-java:typeIs('junit.framework.TestCase')]
@@ -2248,7 +2248,7 @@ The rule is replaced by {% rule java/errorprone/ProperLogger %}.
  [../Type/ReferenceType
   /ClassOrInterfaceType[@Image='Logger']
    and
-  (..[@Final='false'] or ..[@Static = 'false'] ) ]
+  (..[@Final= false()] or ..[@Static = false()] ) ]
 ]]>
                 </value>
             </property>
@@ -2333,7 +2333,7 @@ Either the check is useless (the variable will never be "null") or it is incorre
 public class Foo {
     void bar() {
         if (a.equals(baz) && a != null) {} // a could be null, misplaced null check
-        
+
         if (a != null && a.equals(baz)) {} // correct null check
     }
 }
@@ -2344,7 +2344,7 @@ public class Foo {
 public class Foo {
     void bar() {
         if (a.equals(baz) || a == null) {} // a could be null, misplaced null check
-        
+
         if (a == null || a.equals(baz)) {} // correct null check
     }
 }
@@ -2372,7 +2372,7 @@ may indicate problematic behaviour. Empty cases are ignored as these indicate an
  + count(BlockStatement//Statement/ReturnStatement)
  + count(BlockStatement//Statement/ContinueStatement)
  + count(BlockStatement//Statement/ThrowStatement)
- + count(BlockStatement//Statement/IfStatement[@Else='true' and Statement[2][ReturnStatement|ContinueStatement|ThrowStatement]]/Statement[1][ReturnStatement|ContinueStatement|ThrowStatement])
+ + count(BlockStatement//Statement/IfStatement[@Else= true() and Statement[2][ReturnStatement|ContinueStatement|ThrowStatement]]/Statement[1][ReturnStatement|ContinueStatement|ThrowStatement])
  + count(SwitchLabel[name(following-sibling::node()) = 'SwitchLabel'])
  + count(SwitchLabel[count(following-sibling::node()) = 0])
   < count (SwitchLabel))]
@@ -2421,7 +2421,7 @@ chain needs an own serialVersionUID field. See also [Should an abstract class ha
                 <value>
 <![CDATA[
 //ClassOrInterfaceDeclaration
-    [@Interface = 'false']
+    [@Interface = false()]
     [count(ClassOrInterfaceBody/ClassOrInterfaceBodyDeclaration
         /FieldDeclaration/VariableDeclarator/VariableDeclaratorId[@Image='serialVersionUID']) = 0]
     [(ImplementsList | ExtendsList)/ClassOrInterfaceType[pmd-java:typeIs('java.io.Serializable')]]
@@ -2460,14 +2460,13 @@ See the property `annotations`.
             <property name="xpath">
                 <value>
 <![CDATA[
-//ClassOrInterfaceDeclaration[@Nested=false()]
+//ClassOrInterfaceDeclaration[@Nested= false()]
 [
   (
     (: at least one constructor :)
     ./ClassOrInterfaceBody/ClassOrInterfaceBodyDeclaration/ConstructorDeclaration
     and
-    (: only private constructors :)
-    count(./ClassOrInterfaceBody/ClassOrInterfaceBodyDeclaration/ConstructorDeclaration) = count(./ClassOrInterfaceBody/ClassOrInterfaceBodyDeclaration/ConstructorDeclaration[@Private=true()])
+    (: only private constructors :)count(./ClassOrInterfaceBody/ClassOrInterfaceBodyDeclaration/ConstructorDeclaration) = count(./ClassOrInterfaceBody/ClassOrInterfaceBodyDeclaration/ConstructorDeclaration[@Private= true()])
     and
     (: all constructors must not be annotated :)
     (every $x in $annotations satisfies
@@ -2475,24 +2474,20 @@ See the property `annotations`.
             ../Annotation/MarkerAnnotation/Name[pmd-java:typeIs($x)]))
   )
   and
-  (: no static methods :)
-  not(.//MethodDeclaration[@Static=true()])
+  (: no static methods :)not(.//MethodDeclaration[@Static= true()])
   and
-  (: no (public, package-private, protected) static fields :)
-  not(.//FieldDeclaration[@Private=false()][@Static=true()])
+  (: no (public, package-private, protected) static fields :)not(.//FieldDeclaration[@Private= false()][@Static= true()])
   and
   (: no nested classes, that are public and static, and have no constructors at all or a public constructor :)
   (: and have a method returning the outer class type :)
-  (: or the inner class extends the outer class :)
-  not(.//ClassOrInterfaceDeclaration[@Nested=true()]
-           [@Public=true()]
-           [@Static=true()]
-           [not(./ClassOrInterfaceBody/ClassOrInterfaceBodyDeclaration/ConstructorDeclaration)
-               or ./ClassOrInterfaceBody/ClassOrInterfaceBodyDeclaration/ConstructorDeclaration[@Public=true()]]
+  (: or the inner class extends the outer class :)not(.//ClassOrInterfaceDeclaration[@Nested= true()]
+           [@Public= true()]
+           [@Static= true()]
+           [not(./ClassOrInterfaceBody/ClassOrInterfaceBodyDeclaration/ConstructorDeclaration) or ./ClassOrInterfaceBody/ClassOrInterfaceBodyDeclaration/ConstructorDeclaration[@Public= true()]]
            [(./ClassOrInterfaceBody/ClassOrInterfaceBodyDeclaration/MethodDeclaration
-                [@Public=true()]
+                [@Public= true()]
                 [./ResultType/Type/ReferenceType/ClassOrInterfaceType
-                    [@Image = //ClassOrInterfaceDeclaration[@Nested=false()]/@SimpleName]
+                    [@Image = //ClassOrInterfaceDeclaration[@Nested= false()]/@SimpleName]
                 ]
             ) or (
                 ./ExtendsList/ClassOrInterfaceType[@Image = //ClassOrInterfaceDeclaration[@Nested=false()]/@SimpleName]
@@ -2788,7 +2783,7 @@ NullPointerExceptions.
 <![CDATA[
 //MethodDeclaration
 [
-(./ResultType/Type[@ArrayType='true'])
+(./ResultType/Type[@ArrayType= true()])
 and
 (./Block/BlockStatement/Statement/ReturnStatement/Expression/PrimaryExpression/PrimaryPrefix/Literal/NullLiteral)
 ]
@@ -2967,9 +2962,9 @@ behavior especially when instances are distributed by the container on several J
     )
     and
     (./ClassOrInterfaceBody/ClassOrInterfaceBodyDeclaration[
-         (./FieldDeclaration[@Static = 'true'])
+         (./FieldDeclaration[@Static = true()])
          and
-         (./FieldDeclaration[@Final = 'false'])
+         (./FieldDeclaration[@Final = false()])
     ])
 ]
 ]]>
@@ -3377,7 +3372,7 @@ To make sure the full stacktrace is printed out, use the logging statement with
 concat(ancestor::ClassOrInterfaceDeclaration/ClassOrInterfaceBody/ClassOrInterfaceBodyDeclaration/FieldDeclaration
 [Type//ClassOrInterfaceType[@Image='Log']]
 /VariableDeclarator/VariableDeclaratorId/@Image, '.'))]]
-[PrimarySuffix/Arguments[@Size='1']]
+[PrimarySuffix/Arguments[@Size= 1]]
 [PrimarySuffix/Arguments//Name/@Image = ancestor::CatchStatement/FormalParameter/VariableDeclaratorId/@Image]
 ]]>
                 </value>
diff --git a/pmd-java/src/main/resources/category/java/multithreading.xml b/pmd-java/src/main/resources/category/java/multithreading.xml
index c1ca1d5c2f..35a0d2ec5c 100644
--- a/pmd-java/src/main/resources/category/java/multithreading.xml
+++ b/pmd-java/src/main/resources/category/java/multithreading.xml
@@ -23,7 +23,7 @@ gets it.
         <priority>3</priority>
         <properties>
             <property name="xpath">
-                <value>//MethodDeclaration[@Synchronized='true']</value>
+                <value>//MethodDeclaration[@Synchronized= true()]</value>
             </property>
         </properties>
         <example>
@@ -102,7 +102,7 @@ the volatile keyword should not be used for maintenance purpose and portability.
         <priority>2</priority>
         <properties>
             <property name="xpath">
-                <value>//FieldDeclaration[contains(@Volatile,'true')]</value>
+                <value>//FieldDeclaration[@Volatile = true()]</value>
             </property>
         </properties>
         <example>
@@ -379,7 +379,7 @@ one is chosen.  The thread chosen is arbitrary; thus its usually safer to call n
                 <value>
 <![CDATA[
 //StatementExpression/PrimaryExpression
-[PrimarySuffix/Arguments[@Size = '0']]
+[PrimarySuffix/Arguments[@Size = 0]]
 [
     PrimaryPrefix[
         ./Name[@Image='notify' or ends-with(@Image,'.notify')]
@@ -403,4 +403,4 @@ one is chosen.  The thread chosen is arbitrary; thus its usually safer to call n
         </example>
     </rule>
 
-</ruleset>
\ No newline at end of file
+</ruleset>
diff --git a/pmd-java/src/main/resources/category/java/performance.xml b/pmd-java/src/main/resources/category/java/performance.xml
index 7d0c75b226..7f1b0e4308 100644
--- a/pmd-java/src/main/resources/category/java/performance.xml
+++ b/pmd-java/src/main/resources/category/java/performance.xml
@@ -850,7 +850,7 @@ You must use new ArrayList<>(Arrays.asList(...)) if that is inconvenient for you
                 <value>
 <![CDATA[
 //Statement[
-    (ForStatement) and (ForStatement//VariableInitializer//Literal[@IntLiteral='true' and @Image='0']) and (count(.//IfStatement)=0)
+    (ForStatement) and (ForStatement//VariableInitializer//Literal[@IntLiteral= true() and @Image='0']) and (count(.//IfStatement)=0)
    ]
    //StatementExpression[
     PrimaryExpression/PrimaryPrefix/Name[
@@ -870,7 +870,7 @@ You must use new ArrayList<>(Arrays.asList(...)) if that is inconvenient for you
    and
    PrimaryExpression/PrimarySuffix/Arguments/ArgumentList/Expression/PrimaryExpression/PrimaryPrefix/Name
    [
-     @Image = ancestor::MethodDeclaration[1]//LocalVariableDeclaration/VariableDeclarator/VariableDeclaratorId[@ArrayType="true"]/@Image
+     @Image = ancestor::MethodDeclaration[1]//LocalVariableDeclaration/VariableDeclarator/VariableDeclaratorId[@ArrayType=true()]/@Image
      or
      @Image = ancestor::MethodDeclaration[1]//FormalParameter/VariableDeclaratorId/@Image
    ]
diff --git a/pmd-javascript/src/main/resources/category/ecmascript/bestpractices.xml b/pmd-javascript/src/main/resources/category/ecmascript/bestpractices.xml
index 52cdac1822..a6ce322d0e 100644
--- a/pmd-javascript/src/main/resources/category/ecmascript/bestpractices.xml
+++ b/pmd-javascript/src/main/resources/category/ecmascript/bestpractices.xml
@@ -82,7 +82,7 @@ Global variables can lead to side-effects that are hard to debug.
             <property name="xpath">
                 <value>
 <![CDATA[
-//Assignment[Name/@GlobalName = 'true']
+//Assignment[Name/@GlobalName = true()]
 ]]>
                 </value>
             </property>
diff --git a/pmd-javascript/src/main/resources/category/ecmascript/codestyle.xml b/pmd-javascript/src/main/resources/category/ecmascript/codestyle.xml
index 285262c59d..04d4e1abb2 100644
--- a/pmd-javascript/src/main/resources/category/ecmascript/codestyle.xml
+++ b/pmd-javascript/src/main/resources/category/ecmascript/codestyle.xml
@@ -25,17 +25,17 @@ indicative of the bug where the assignment operator '=' was used instead of the
             <property name="xpath">
                 <value>
 <![CDATA[
-    //IfStatement[$allowIf = "false"]/child::node()[1]/descendant-or-self::node()[self::Assignment or self::UnaryExpression[$allowIncrementDecrement = "false" and (@Image = "--" or @Image = "++")]]
+    //IfStatement[$allowIf = false()]/child::node()[1]/descendant-or-self::node()[self::Assignment or self::UnaryExpression[$allowIncrementDecrement = false() and (@Image = "--" or @Image = "++")]]
 |
-    //WhileLoop[$allowWhile = "false"]/child::node()[1]/descendant-or-self::node()[self::Assignment or self::UnaryExpression[$allowIncrementDecrement = "false" and (@Image = "--" or @Image = "++")]]
+    //WhileLoop[$allowWhile = false()]/child::node()[1]/descendant-or-self::node()[self::Assignment or self::UnaryExpression[$allowIncrementDecrement = false() and (@Image = "--" or @Image = "++")]]
 |
-    //DoLoop[$allowWhile = "false"]/child::node()[2]/descendant-or-self::node()[self::Assignment or self::UnaryExpression[$allowIncrementDecrement = "false" and (@Image = "--" or @Image = "++")]]
+    //DoLoop[$allowWhile = false()]/child::node()[2]/descendant-or-self::node()[self::Assignment or self::UnaryExpression[$allowIncrementDecrement = false() and (@Image = "--" or @Image = "++")]]
 |
-    //ForLoop[$allowFor = "false"]/child::node()[2]/descendant-or-self::node()[self::Assignment or self::UnaryExpression[$allowIncrementDecrement = "false" and (@Image = "--" or @Image = "++")]]
+    //ForLoop[$allowFor = false()]/child::node()[2]/descendant-or-self::node()[self::Assignment or self::UnaryExpression[$allowIncrementDecrement = false() and (@Image = "--" or @Image = "++")]]
 |
-   //ConditionalExpression[$allowTernary = "false"]/child::node()[1]/descendant-or-self::node()[self::Assignment or self::UnaryExpression[$allowIncrementDecrement = "false" and (@Image = "--" or @Image = "++")]]
+   //ConditionalExpression[$allowTernary = false()]/child::node()[1]/descendant-or-self::node()[self::Assignment or self::UnaryExpression[$allowIncrementDecrement = false() and (@Image = "--" or @Image = "++")]]
 |
-   //ConditionalExpression[$allowTernaryResults = "false"]/child::node()[position() = 2 or position() = 3]/descendant-or-self::node()[self::Assignment or self::UnaryExpression[$allowIncrementDecrement = "false" and (@Image = "--" or @Image = "++")]]
+   //ConditionalExpression[$allowTernaryResults = false()]/child::node()[position() = 2 or position() = 3]/descendant-or-self::node()[self::Assignment or self::UnaryExpression[$allowIncrementDecrement = false() and (@Image = "--" or @Image = "++")]]
 ]]>
                 </value>
             </property>
@@ -110,7 +110,7 @@ Avoid using if..else statements without using curly braces.
             <property name="xpath">
                 <value>
 <![CDATA[
-//ExpressionStatement[parent::IfStatement[@Else = "true"]]
+//ExpressionStatement[parent::IfStatement[@Else = true()]]
    [not(child::Scope)]
    [not(child::IfStatement)]
 ]]>
@@ -149,7 +149,7 @@ Avoid using if statements without using curly braces.
             <property name="xpath">
                 <value>
 <![CDATA[
-//IfStatement[@Else = "false" and not(child::Scope)]
+//IfStatement[@Else = false() and not(child::Scope)]
 ]]>
                 </value>
             </property>
diff --git a/pmd-javascript/src/main/resources/category/ecmascript/errorprone.xml b/pmd-javascript/src/main/resources/category/ecmascript/errorprone.xml
index 4b48e85dfe..a39190db2e 100644
--- a/pmd-javascript/src/main/resources/category/ecmascript/errorprone.xml
+++ b/pmd-javascript/src/main/resources/category/ecmascript/errorprone.xml
@@ -23,9 +23,9 @@ This rule helps improve code portability due to differences in browser treatment
             <property name="xpath">
                 <value>
 <![CDATA[
-//ObjectLiteral[$allowObjectLiteral = "false" and @TrailingComma = 'true']
+//ObjectLiteral[$allowObjectLiteral = false() and @TrailingComma = true()]
 |
-//ArrayLiteral[$allowArrayLiteral = "false" and @TrailingComma = 'true']
+//ArrayLiteral[$allowArrayLiteral = false() and @TrailingComma = true()]
 ]]>
                 </value>
             </property>
@@ -62,7 +62,7 @@ same type. The === operator avoids the casting.
 <![CDATA[
 //InfixExpression[(@Image = "==" or @Image = "!=")
   and
- (child::KeywordLiteral[@Image = "true" or @Image = "false"]
+ (child::KeywordLiteral[@Image = true() or @Image = false()]
  or
  child::NumberLiteral)
 ]
diff --git a/pmd-plsql/src/main/resources/category/plsql/codestyle.xml b/pmd-plsql/src/main/resources/category/plsql/codestyle.xml
index 62a22d0a4c..2e01fea8c7 100644
--- a/pmd-plsql/src/main/resources/category/plsql/codestyle.xml
+++ b/pmd-plsql/src/main/resources/category/plsql/codestyle.xml
@@ -150,13 +150,13 @@ In case you have loops please name the loop variables more meaningful.
                 <value>
 <![CDATA[
 //CursorForLoopStatement[
-    $allowSimpleLoops = 'false' or
+    $allowSimpleLoops = false() or
     (Statement//CursorForLoopStatement or ancestor::CursorForLoopStatement)
 ]
 /ForIndex[not(matches(@Image, $cursorPattern))]
 |
 //ForStatement[
-    $allowSimpleLoops = 'false' or
+    $allowSimpleLoops = false() or
     (Statement//ForStatement or ancestor::ForStatement)
 ]
 /ForIndex[not(matches(@Image, $indexPattern))]
diff --git a/pmd-xml/src/main/resources/category/xsl/performance.xml b/pmd-xml/src/main/resources/category/xsl/performance.xml
index ebb954b755..c23f1a8642 100644
--- a/pmd-xml/src/main/resources/category/xsl/performance.xml
+++ b/pmd-xml/src/main/resources/category/xsl/performance.xml
@@ -38,7 +38,7 @@ cutting through 100% of the document.
   or
   contains(@select,'descendant-self::')
   or (
-    ($checkSelfDescendantAbreviation = 'true' )
+    ($checkSelfDescendantAbreviation = true() )
     and
     contains(@select,'//')
     )