Add empty mml:mi error

src/final-JATS-schematron.sch

@@ -2953,7 +2953,9 @@
 
     </rule></pattern><pattern id="math-mi-tests-pattern"><rule context="mml:mi" id="math-mi-tests">
 
-      <report test="matches(.,'^\p{Zs}$')" role="error" id="math-mi-space-test">[math-mi-space-test] <name/> element contains only text. Has "\" been used for space in the tex editor, instead of "\,"?</report>
+      <report test="matches(.,'^\p{Zs}$')" role="error" id="math-mi-space-test">[math-mi-space-test] <name/> element contains only spaces. Has "\" been used for space in the tex editor, instead of "\,"?</report>
+
+      <report test="not(*) and normalize-space(.)=''" role="error" id="math-mi-empty-test">[math-mi-empty-test] <name/> element is completely empty. This is not allowed.</report>
 
     </rule></pattern><pattern id="disp-formula-child-tests-pattern"><rule context="disp-formula/*" id="disp-formula-child-tests">
 

src/final-JATS-schematron.xsl

@@ -16364,7 +16364,21 @@
             </xsl:attribute>
             <svrl:text>[math-mi-space-test] <xsl:text/>
                <xsl:value-of select="name(.)"/>
-               <xsl:text/> element contains only text. Has "\" been used for space in the tex editor, instead of "\,"?</svrl:text>
+               <xsl:text/> element contains only spaces. Has "\" been used for space in the tex editor, instead of "\,"?</svrl:text>
+         </svrl:successful-report>
+      </xsl:if>
+
+		    <!--REPORT error-->
+      <xsl:if test="not(*) and normalize-space(.)=''">
+         <svrl:successful-report xmlns:svrl="http://purl.oclc.org/dsdl/svrl" test="not(*) and normalize-space(.)=''">
+            <xsl:attribute name="id">math-mi-empty-test</xsl:attribute>
+            <xsl:attribute name="role">error</xsl:attribute>
+            <xsl:attribute name="location">
+               <xsl:apply-templates select="." mode="schematron-select-full-path"/>
+            </xsl:attribute>
+            <svrl:text>[math-mi-empty-test] <xsl:text/>
+               <xsl:value-of select="name(.)"/>
+               <xsl:text/> element is completely empty. This is not allowed.</svrl:text>
          </svrl:successful-report>
       </xsl:if>
       <xsl:apply-templates select="*" mode="M208"/>

src/final-package-JATS-schematron.sch

@@ -2959,7 +2959,9 @@
 
     </rule></pattern><pattern id="math-mi-tests-pattern"><rule context="mml:mi" id="math-mi-tests">
 
-      <report test="matches(.,'^\p{Zs}$')" role="error" id="math-mi-space-test"><name/> element contains only text. Has "\" been used for space in the tex editor, instead of "\,"?</report>
+      <report test="matches(.,'^\p{Zs}$')" role="error" id="math-mi-space-test"><name/> element contains only spaces. Has "\" been used for space in the tex editor, instead of "\,"?</report>
+
+      <report test="not(*) and normalize-space(.)=''" role="error" id="math-mi-empty-test"><name/> element is completely empty. This is not allowed.</report>
 
     </rule></pattern><pattern id="disp-formula-child-tests-pattern"><rule context="disp-formula/*" id="disp-formula-child-tests">
 

src/pre-JATS-schematron.sch

@@ -2898,7 +2898,9 @@
 
     </rule></pattern><pattern id="math-mi-tests-pattern"><rule context="mml:mi" id="math-mi-tests">
 
-      <report test="matches(.,'^\p{Zs}$')" role="error" id="math-mi-space-test">[math-mi-space-test] <name/> element contains only text. Has "\" been used for space in the tex editor, instead of "\,"?</report>
+      <report test="matches(.,'^\p{Zs}$')" role="error" id="math-mi-space-test">[math-mi-space-test] <name/> element contains only spaces. Has "\" been used for space in the tex editor, instead of "\,"?</report>
+
+      <report test="not(*) and normalize-space(.)=''" role="error" id="math-mi-empty-test">[math-mi-empty-test] <name/> element is completely empty. This is not allowed.</report>
 
     </rule></pattern><pattern id="disp-formula-child-tests-pattern"><rule context="disp-formula/*" id="disp-formula-child-tests">
 

src/pre-JATS-schematron.xsl

@@ -16230,7 +16230,21 @@
             </xsl:attribute>
             <svrl:text>[math-mi-space-test] <xsl:text/>
                <xsl:value-of select="name(.)"/>
-               <xsl:text/> element contains only text. Has "\" been used for space in the tex editor, instead of "\,"?</svrl:text>
+               <xsl:text/> element contains only spaces. Has "\" been used for space in the tex editor, instead of "\,"?</svrl:text>
+         </svrl:successful-report>
+      </xsl:if>
+
+		    <!--REPORT error-->
+      <xsl:if test="not(*) and normalize-space(.)=''">
+         <svrl:successful-report xmlns:svrl="http://purl.oclc.org/dsdl/svrl" test="not(*) and normalize-space(.)=''">
+            <xsl:attribute name="id">math-mi-empty-test</xsl:attribute>
+            <xsl:attribute name="role">error</xsl:attribute>
+            <xsl:attribute name="location">
+               <xsl:apply-templates select="." mode="schematron-select-full-path"/>
+            </xsl:attribute>
+            <svrl:text>[math-mi-empty-test] <xsl:text/>
+               <xsl:value-of select="name(.)"/>
+               <xsl:text/> element is completely empty. This is not allowed.</svrl:text>
          </svrl:successful-report>
       </xsl:if>
       <xsl:apply-templates select="*" mode="M206"/>

src/schematron.sch

@@ -4763,7 +4763,11 @@ else self::*/local-name() = $allowed-p-blocks"
 
       <report test="matches(.,'^\p{Zs}$')"
         role="error"
-        id="math-mi-space-test"><name/> element contains only text. Has "\" been used for space in the tex editor, instead of "\,"?</report>
+        id="math-mi-space-test"><name/> element contains only spaces. Has "\" been used for space in the tex editor, instead of "\,"?</report>
+
+      <report test="not(*) and normalize-space(.)=''"
+        role="error"
+        id="math-mi-empty-test"><name/> element is completely empty. This is not allowed.</report>
 
     </rule>
 

test/tests/gen/math-mi-tests/math-mi-empty-test/fail.xml

@@ -0,0 +1,9 @@
+<?oxygen SCHSchema="math-mi-empty-test.sch"?>
+<!--Context: mml:mi
+Test: report    not(*) and normalize-space(.)=''
+Message:  element is completely empty. This is not allowed. -->
+<root xmlns:ali="http://www.niso.org/schemas/ali/1.0/" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">
+    <article>
+        <inline-formula><mml:math id="inf1"><mml:mstyle displaystyle="true" scriptlevel="0"><mml:mrow class="MJX-TeXAtom-ORD"><mml:mover><mml:mi/><mml:mo stretchy="false">¯</mml:mo></mml:mover></mml:mrow></mml:mstyle></mml:math></inline-formula>
+    </article>
+</root>