diff --git a/format-master.xml b/format-master.xml
index 380ca72..f91bfb7 100755
--- a/format-master.xml
+++ b/format-master.xml
@@ -251,6 +251,11 @@
 		<html><xsl:text disable-output-escaping="yes">&amp;Phi;</xsl:text></html>
 	</template>
 
+	<template name="empty-set-sign" match="empty-set-sign|empty-set|null">
+		<latex>\ensuremath{\emptyset}</latex>
+		<html><xsl:text disable-output-escaping="yes">&amp;#8709;</xsl:text></html>
+	</template>
+
 	<template name="element-sign" match="element-sign|element|element-of|is-element-of|is-an-element-of">
 		<latex>\ensuremath{\in}</latex>
 		<html><xsl:text disable-output-escaping="yes">&amp;#8712;</xsl:text></html>
@@ -398,6 +403,11 @@
 		<html><xsl:text disable-output-escaping="yes">&amp;#8744;</xsl:text></html>
 	</template>
 
+	<template name="logical-not-operator" match="logical-negation-operator|logical-negation|logical-not|not|negation|neg">
+		<latex>\ensuremath{\neg}</latex>
+		<html><xsl:text disable-output-escaping="yes">&amp;#172;</xsl:text></html>
+	</template>
+
 	<template name="LaTeX" match="LaTeX|latex">
 		<latex>{\LaTeX}</latex>
 		<html>L<SUP>A</SUP>T<SUB>E</SUB>X</html>
