diff --git a/format-master.xml b/format-master.xml
index a8e5ec2..cd97d37 100755
--- a/format-master.xml
+++ b/format-master.xml
@@ -279,25 +279,25 @@
 
 	<!-- I think the pi symbol is only available in LaTeX in math mode, but if we're already in math mode, the extra $ signs will mess things up... -->
 	<!-- Use \ensuremath to resolve the problem. -->
-	<template name="epsilon" match="epsilon|extend|greek-small-letter-epsilon">
+	<template name="epsilon" match="epsilon|greek-small-letter-epsilon">
 		<common formats="/latex/xelatex/">\ensuremath{\epsilon}</common>
 		<html><xsl:text disable-output-escaping="yes">&amp;epsilon;</xsl:text></html>
 		<!-- U+03B5 GREEK SMALL LETTER EPSILON -->
 		<xhtml><span class="unicode"><xsl:text>ε</xsl:text></span></xhtml>
 	</template>
-	<template name="pi" match="pi|project|greek-small-letter-pi">
+	<template name="pi" match="pi|greek-small-letter-pi">
 		<common formats="/latex/xelatex/">\ensuremath{\pi}</common>
 		<html><xsl:text disable-output-escaping="yes">&amp;pi;</xsl:text></html>
 		<!-- U+03C0 GREEK SMALL LETTER PI -->
 		<xhtml><span class="unicode"><xsl:text>π</xsl:text></span></xhtml>
 	</template>
-	<template name="rho" match="rho|rename|greek-small-letter-rho">
+	<template name="rho" match="rho|greek-small-letter-rho">
 		<common formats="/latex/xelatex/">\ensuremath{\rho}</common>
 		<html><xsl:text disable-output-escaping="yes">&amp;rho;</xsl:text></html>
 		<!-- U+03C1 GREEK SMALL LETTER RHO -->
 		<xhtml><span class="unicode"><xsl:text>ρ</xsl:text></span></xhtml>
 	</template>
-	<template name="sigma" match="sigma|restrict|greek-small-letter-sigma">
+	<template name="sigma" match="sigma|greek-small-letter-sigma">
 		<common formats="/latex/xelatex/">\ensuremath{\sigma}</common>
 		<html><xsl:text disable-output-escaping="yes">&amp;sigma;</xsl:text></html>
 		<!-- U+03C3 GREEK SMALL LETTER SIGMA -->
@@ -309,7 +309,7 @@
 		<!-- U+03A6 GREEK CAPITAL LETTER PHI -->
 		<xhtml><span class="unicode"><xsl:text>Φ</xsl:text></span></xhtml>
 	</template>
-
+	
 	<template name="empty-set-sign" match="empty-set-sign|empty-set|null">
 		<common formats="/latex/xelatex/">\ensuremath{\emptyset}</common>
 		<html><xsl:text disable-output-escaping="yes">&amp;empty;</xsl:text></html>
@@ -345,8 +345,130 @@
 		<xhtml><span class="unicode"><xsl:text>⊃</xsl:text></span></xhtml>
 	</template>
 
-	<template name="join-operator" match="join-operator|join|natural-join|bowtie">
-		<common formats="/latex/xelatex/">\ensuremath{\Join}</common>
+	<!--
+		Relational algebra operators. These are distinct from the basic Greek
+		characters, because they can have associated subscripts (i.e., they
+		have arguments). These also use relalg.sty in (Xe)LaTeX for general
+		consistency.
+	-->
+	<template name="project" match="project">
+		<common formats="/latex/xelatex/">
+			<xsl:text>\ensuremath{\RelProject</xsl:text>
+			<xsl:if test="* | text()">
+				<xsl:text>_{</xsl:text>
+					<xsl:apply-templates />
+				<xsl:text>}</xsl:text>
+			</xsl:if>
+			<xsl:text>}</xsl:text>
+		</common>
+		<html>
+			<xsl:text disable-output-escaping="yes">&amp;pi;</xsl:text>
+			<xsl:if test="* | text()">
+				<sub><xsl:apply-templates /></sub>
+			</xsl:if>
+			<xsl:text disable-output-escaping="yes">&amp;thinsp;</xsl:text>
+		</html>
+		<!-- U+03C0 GREEK SMALL LETTER PI -->
+		<xhtml>
+			<span class="unicode"><xsl:text>π</xsl:text></span>
+			<xsl:if test="* | text()">
+				<sub><xsl:apply-templates /></sub>
+			</xsl:if>
+			<xsl:text disable-output-escaping="yes">&amp;thinsp;</xsl:text>
+		</xhtml>
+	</template>
+	
+	<template name="extend" match="extend">
+		<common formats="/latex/xelatex/">
+			<xsl:text>\ensuremath{\RelExtend</xsl:text>
+			<xsl:if test="* | text()">
+				<xsl:text>_{</xsl:text>
+					<xsl:apply-templates />
+				<xsl:text>}</xsl:text>
+			</xsl:if>
+			<xsl:text>}</xsl:text>
+		</common>
+		<html>
+			<xsl:text disable-output-escaping="yes">&amp;epsilon;</xsl:text>
+			<xsl:if test="* | text()">
+				<sub><xsl:apply-templates /></sub>
+			</xsl:if>
+			<xsl:text disable-output-escaping="yes">&amp;thinsp;</xsl:text>
+		</html>
+		<!-- U+03B5 GREEK SMALL LETTER EPSILON -->
+		<xhtml>
+			<span class="unicode"><xsl:text>ε</xsl:text></span>
+			<xsl:if test="* | text()">
+				<sub><xsl:apply-templates /></sub>
+			</xsl:if>
+			<xsl:text disable-output-escaping="yes">&amp;thinsp;</xsl:text>
+		</xhtml>
+	</template>
+	
+	<template name="rename" match="rename">
+		<common formats="/latex/xelatex/">
+			<xsl:text>\ensuremath{\RelRename</xsl:text>
+			<xsl:if test="* | text()">
+				<xsl:text>_{</xsl:text>
+					<xsl:apply-templates />
+				<xsl:text>}</xsl:text>
+			</xsl:if>
+			<xsl:text>}</xsl:text>
+		</common>
+		<html>
+			<xsl:text disable-output-escaping="yes">&amp;rho;</xsl:text>
+			<xsl:if test="* | text()">
+				<sub><xsl:apply-templates /></sub>
+			</xsl:if>
+			<xsl:text disable-output-escaping="yes">&amp;thinsp;</xsl:text>
+		</html>
+		<!-- U+03C0 GREEK SMALL LETTER PI -->
+		<xhtml>
+			<span class="unicode"><xsl:text>ρ</xsl:text></span>
+			<xsl:if test="* | text()">
+				<sub><xsl:apply-templates /></sub>
+			</xsl:if>
+			<xsl:text disable-output-escaping="yes">&amp;thinsp;</xsl:text>
+		</xhtml>
+	</template>
+	
+	<template name="restrict" match="restrict">
+		<common formats="/latex/xelatex/">
+			<xsl:text>\ensuremath{\RelRestrict</xsl:text>
+			<xsl:if test="* | text()">
+				<xsl:text>_{</xsl:text>
+					<xsl:apply-templates />
+				<xsl:text>}</xsl:text>
+			</xsl:if>
+			<xsl:text>}</xsl:text>
+		</common>
+		<html>
+			<xsl:text disable-output-escaping="yes">&amp;sigma;</xsl:text>
+			<xsl:if test="* | text()">
+				<sub><xsl:apply-templates /></sub>
+			</xsl:if>
+			<xsl:text disable-output-escaping="yes">&amp;thinsp;</xsl:text>
+		</html>
+		<!-- U+03C0 GREEK SMALL LETTER PI -->
+		<xhtml>
+			<span class="unicode"><xsl:text>σ</xsl:text></span>
+			<xsl:if test="* | text()">
+				<sub><xsl:apply-templates /></sub>
+			</xsl:if>
+			<xsl:text disable-output-escaping="yes">&amp;thinsp;</xsl:text>
+		</xhtml>
+	</template>
+
+	<template name="join-operator" match="join-operator|join|natural-join|inner-join|bowtie">
+		<common formats="/latex/xelatex/">
+			<xsl:text>\ensuremath{\RelNaturalJoin</xsl:text>
+			<xsl:if test="* | text()">
+				<xsl:text>_{</xsl:text>
+					<xsl:apply-templates />
+				<xsl:text>}</xsl:text>
+			</xsl:if>
+			<xsl:text>}</xsl:text>
+		</common>
 		<!--
 			No easy way at present to get the join symbol in HTML, so
 			just use an image. Scale it to 10x10 pixels (fine as long as
@@ -355,7 +477,9 @@
 			We need to ensure that the path is absolute, because we don't
 			necessarily know where the document will end up in the tree.
 		-->
+		<!-- Need spaces for HTML as they seem to get munched otherwise. -->
 		<html>
+			<xsl:text> </xsl:text>
 			<img>
 				<xsl:attribute name="src">
 					<xsl:text>/</xsl:text>
@@ -376,6 +500,10 @@
 					<xsl:text>padding-left:0.3em;padding-right:0.3em</xsl:text>
 				</xsl:attribute>
 			</img>
+			<xsl:if test="* | text()">
+				<sub><xsl:apply-templates /></sub>
+			</xsl:if>
+			<xsl:text> </xsl:text>
 		</html>
 		<!--
 			Note that we use the Unicode BOWTIE character (U+22C8) rather
@@ -384,7 +512,14 @@
 			have any significant effect.
 		-->
 		<!-- U+22C8 BOWTIE -->
-		<xhtml><span class="unicode"><xsl:text>⋈</xsl:text></span></xhtml>
+		<xhtml>
+			<xsl:text> </xsl:text>
+			<span class="unicode"><xsl:text>⋈</xsl:text></span>
+			<xsl:if test="* | text()">
+				<sub><xsl:apply-templates /></sub>
+			</xsl:if>
+			<xsl:text> </xsl:text>
+		</xhtml>
 	</template>
 
 	<!--
@@ -407,7 +542,13 @@
 					<xsl:text>Full</xsl:text>
 				</xsl:otherwise>
 			</xsl:choose>
-			<xsl:text>OuterJoin}</xsl:text>
+			<xsl:text>OuterJoin</xsl:text>
+			<xsl:if test="* | text()">
+				<xsl:text>_{</xsl:text>
+					<xsl:apply-templates />
+				<xsl:text>}</xsl:text>
+			</xsl:if>
+			<xsl:text>}</xsl:text>
 		</common>
 		<!--
 			No easy way at present to get a join symbol in HTML, so
@@ -418,7 +559,9 @@
 			We need to ensure that the path is absolute, because we don't
 			necessarily know where the document will end up in the tree.
 		-->
+		<!-- Need spaces for HTML as they seem to get munched otherwise. -->
 		<common formats="/html/xhtml/">
+			<xsl:text> </xsl:text>
 			<img>
 				<xsl:attribute name="src">
 					<xsl:text>/</xsl:text>
@@ -466,6 +609,10 @@
 					<xsl:text>padding-left:0.3em;padding-right:0.3em</xsl:text>
 				</xsl:attribute>
 			</img>
+			<xsl:if test="* | text()">
+				<sub><xsl:apply-templates /></sub>
+			</xsl:if>
+			<xsl:text> </xsl:text>
 		</common>
 		<!-- 
 			Note that these characters are available in Unicode (U+27D5
@@ -475,6 +622,7 @@
 		-->
 <!-- 
 		<xhtml>
+			<xsl:text> </xsl:text>
 			<xsl:choose>
 				<xsl:when test="@type = 'left'">
 					<span class="unicode"><xsl:text>⟕</xsl:text></span>
@@ -486,36 +634,44 @@
 					<span class="unicode"><xsl:text>⟗</xsl:text></span>
 				</xsl:otherwise>
 			</xsl:choose>
+			<xsl:if test="* | text()">
+				<sub><xsl:apply-templates /></sub>
+			</xsl:if>
+			<xsl:text> </xsl:text>
 		</xhtml>
  -->
 	</template>
 
 	<template name="intersect-operator" match="intersect-operator|intersect|intersection|cap">
 		<common formats="/latex/xelatex/">\ensuremath{\cap}</common>
-		<html><xsl:text disable-output-escaping="yes">&amp;cap;</xsl:text></html>
+		<!-- Need spaces for HTML as they seem to get munched otherwise. -->
+		<html><xsl:text disable-output-escaping="yes"> &amp;cap; </xsl:text></html>
 		<!-- U+2229 INTERSECTION -->
-		<xhtml><span class="unicode"><xsl:text>∩</xsl:text></span></xhtml>
+		<xhtml><span class="unicode"><xsl:text> ∩ </xsl:text></span></xhtml>
 	</template>
 
 	<template name="union-operator" match="union-operator|union|cup">
 		<common formats="/latex/xelatex/">\ensuremath{\cup}</common>
-		<html><xsl:text disable-output-escaping="yes">&amp;cup;</xsl:text></html>
+		<!-- Need spaces for HTML as they seem to get munched otherwise. -->
+		<html><xsl:text disable-output-escaping="yes"> &amp;cup; </xsl:text></html>
 		<!-- U+222A UNION -->
-		<xhtml><span class="unicode"><xsl:text>∪</xsl:text></span></xhtml>
+		<xhtml><span class="unicode"><xsl:text> ∪ </xsl:text></span></xhtml>
 	</template>
 
 	<template name="logical-and-operator" match="logical-and-operator|logical-and|and|and-operator|hat|wedge">
 		<common formats="/latex/xelatex/">\ensuremath{\wedge}</common>
-		<html><xsl:text disable-output-escaping="yes">&amp;and;</xsl:text></html>
+		<!-- Need spaces for HTML as they seem to get munched otherwise. -->
+		<html><xsl:text disable-output-escaping="yes"> &amp;and; </xsl:text></html>
 		<!-- U+2227 LOGICAL AND -->
-		<xhtml><span class="unicode"><xsl:text>∧</xsl:text></span></xhtml>
+		<xhtml><span class="unicode"><xsl:text> ∧ </xsl:text></span></xhtml>
 	</template>
 
 	<template name="logical-or-operator" match="logical-or-operator|logical-or|or|or-operator|vee">
 		<common formats="/latex/xelatex/">\ensuremath{\vee}</common>
-		<html><xsl:text disable-output-escaping="yes">&amp;or;</xsl:text></html>
+		<!-- Need spaces for HTML as they seem to get munched otherwise. -->
+		<html><xsl:text disable-output-escaping="yes"> &amp;or; </xsl:text></html>
 		<!-- U+2228 LOGICAL OR -->
-		<xhtml><span class="unicode"><xsl:text>∨</xsl:text></span></xhtml>
+		<xhtml><span class="unicode"><xsl:text> ∨ </xsl:text></span></xhtml>
 	</template>
 
 	<template name="logical-not-operator" match="logical-not-operator|logical-negation-operator|logical-negation|logical-not|not|negation|neg|not-sign">
@@ -533,6 +689,7 @@
 	<!-- Note: no equivalent of \triangleright in HTML, use right arrow instead. -->
 	<template name="menu-separator" match="menu-separator|menusep|menu/separator">
 		<common formats="/latex/xelatex/"> \ensuremath{\triangleright} </common>
+		<!-- Need spaces for HTML as they seem to get munched otherwise. -->
 		<html><xsl:text disable-output-escaping="yes"> &amp;rarr; </xsl:text></html>
 		<!-- U+25B9 WHITE RIGHT-POINTING SMALL TRIANGLE -->
 		<xhtml><span class="unicode"><xsl:text> ▹ </xsl:text></span></xhtml>
@@ -2792,20 +2949,21 @@
 	-->
 	<template name="right-arrow" match="right-arrow|rightarrow|implies|rarr|rarrow|rightwards-arrow">
 		<common formats="/latex/xelatex/">
-			<xsl:text> \ensuremath{\</xsl:text>
+			<xsl:text>\ensuremath{\</xsl:text>
 			<xsl:choose>
 				<xsl:when test="@weight='double'">R</xsl:when>
 				<xsl:otherwise>r</xsl:otherwise>
 			</xsl:choose>
-			<xsl:text>ightarrow} </xsl:text>
+			<xsl:text>ightarrow}</xsl:text>
 		</common>
+		<!-- Need spaces for HTML as they seem to get munched otherwise. -->
 		<html>
 			<xsl:choose>
 				<xsl:when test="@weight='double'">
-					<xsl:text disable-output-escaping="yes">&amp;rArr;</xsl:text>
+					<xsl:text disable-output-escaping="yes"> &amp;rArr; </xsl:text>
 				</xsl:when>
 				<xsl:otherwise>
-					<xsl:text disable-output-escaping="yes">&amp;rarr;</xsl:text>
+					<xsl:text disable-output-escaping="yes"> &amp;rarr; </xsl:text>
 				</xsl:otherwise>
 			</xsl:choose>
 		</html>
@@ -2814,12 +2972,12 @@
 				<xsl:when test="@weight='double'">
 					<!-- U+21D2 RIGHTWARDS DOUBLE ARROW -->
 					<span class="unicode">
-						<xsl:text>⇒</xsl:text>
+						<xsl:text> ⇒ </xsl:text>
 					</span>
 				</xsl:when>
 				<xsl:otherwise>
 					<!-- U+2192 RIGHTWARDS ARROW -->
-					<xsl:text>→</xsl:text>
+					<xsl:text> → </xsl:text>
 				</xsl:otherwise>
 			</xsl:choose>
 		</xhtml>
@@ -2832,20 +2990,21 @@
 	-->
 	<template name="left-arrow" match="left-arrow|leftarrow|larr|larrow|leftwards-arrow">
 		<common formats="/latex/xelatex/">
-			<xsl:text> \ensuremath{\</xsl:text>
+			<xsl:text>\ensuremath{\</xsl:text>
 			<xsl:choose>
 				<xsl:when test="@weight='double'">L</xsl:when>
 				<xsl:otherwise>l</xsl:otherwise>
 			</xsl:choose>
-			<xsl:text>eftarrow} </xsl:text>
+			<xsl:text>eftarrow}</xsl:text>
 		</common>
+		<!-- Need spaces for HTML as they seem to get munched otherwise. -->
 		<html>
 			<xsl:choose>
 				<xsl:when test="@weight='double'">
-					<xsl:text disable-output-escaping="yes">&amp;lArr;</xsl:text>
+					<xsl:text disable-output-escaping="yes"> &amp;lArr; </xsl:text>
 				</xsl:when>
 				<xsl:otherwise>
-					<xsl:text disable-output-escaping="yes">&amp;larr;</xsl:text>
+					<xsl:text disable-output-escaping="yes"> &amp;larr; </xsl:text>
 				</xsl:otherwise>
 			</xsl:choose>
 		</html>
@@ -2853,11 +3012,11 @@
 			<xsl:choose>
 				<xsl:when test="@weight='double'">
 					<!-- U+21D0 LEFTWARDS DOUBLE ARROW -->
-					<xsl:text>⇐</xsl:text>
+					<xsl:text> ⇐ </xsl:text>
 				</xsl:when>
 				<xsl:otherwise>
 					<!-- U+2190 LEFTWARDS ARROW -->
-					<xsl:text>←</xsl:text>
+					<xsl:text> ← </xsl:text>
 				</xsl:otherwise>
 			</xsl:choose>
 		</xhtml>
