diff --git a/Lectures/L24_SpecificationQuality/SpecificationQuality.pdf b/Lectures/L24_SpecificationQuality/SpecificationQuality.pdf
index ca652318e7186cfeb073ead1e65604aaef76a226..ed786ac0e49d96f66a22cf2b8630261db6816728 100644
Binary files a/Lectures/L24_SpecificationQuality/SpecificationQuality.pdf and b/Lectures/L24_SpecificationQuality/SpecificationQuality.pdf differ
diff --git a/Lectures/L24_SpecificationQuality/SpecificationQuality.tex b/Lectures/L24_SpecificationQuality/SpecificationQuality.tex
index 1f2592a2cd28d251752c19a5ada269d1be1d036c..704fa43ec48e69a27eaa67a913a8f49935c714cd 100755
--- a/Lectures/L24_SpecificationQuality/SpecificationQuality.tex
+++ b/Lectures/L24_SpecificationQuality/SpecificationQuality.tex
@@ -25,7 +25,7 @@
 \input{../def-beamer}
 \Draftfalse
 
-\newcommand{\topicTitle}{26 Specification Quality}
+\newcommand{\topicTitle}{24 Specification Quality}
 \ifDraft
 \newcommand{\topic}{\topicTitle~DRAFT}
 \else
diff --git a/Lectures/L25_EnglishToMath/EnglishToMath.tex b/Lectures/L25_EnglishToMath/EnglishToMath.tex
index daf11291c8054768e584089eaaa87fc89964f467..61669eb95585973fe1aff6351e9a3ab637a16930 100755
--- a/Lectures/L25_EnglishToMath/EnglishToMath.tex
+++ b/Lectures/L25_EnglishToMath/EnglishToMath.tex
@@ -25,7 +25,7 @@
 \input{../def-beamer}
 \Drafttrue
 
-\newcommand{\topicTitle}{27 English To Math}
+\newcommand{\topicTitle}{25 English To Math}
 \ifDraft
 \newcommand{\topic}{\topicTitle~DRAFT}
 \else
diff --git a/Lectures/L26_TemplatesInCpp/GenericsAndInterfacesInJava.tex b/Lectures/L26_TemplatesInCpp/GenericsAndInterfacesInJava.tex
index 92d07864148039ea19142522bc3f8670faa380fd..21a27fc6819aabe9c5d7e2fdba1ee4545d2da7b0 100755
--- a/Lectures/L26_TemplatesInCpp/GenericsAndInterfacesInJava.tex
+++ b/Lectures/L26_TemplatesInCpp/GenericsAndInterfacesInJava.tex
@@ -25,7 +25,7 @@
 \input{../def-beamer}
 \Drafttrue
 
-\newcommand{\topicTitle}{24 Generics and Interfaces in Java}
+\newcommand{\topicTitle}{26 Generics and Interfaces in Java}
 \ifDraft
 \newcommand{\topic}{\topicTitle~DRAFT}
 \else
diff --git a/Lectures/L27_SpecViaUML/SpecViaUML.tex b/Lectures/L27_SpecViaUML/SpecViaUML.tex
index 19818857ad270aca6044c114e52763f62003dc79..ed9af30abc690638c8e624111f2a31ddc8e91461 100755
--- a/Lectures/L27_SpecViaUML/SpecViaUML.tex
+++ b/Lectures/L27_SpecViaUML/SpecViaUML.tex
@@ -25,7 +25,7 @@
 \input{../def-beamer}
 \Drafttrue
 
-\newcommand{\topicTitle}{25 Specification Via UML (Ch.\ 5 and others)}
+\newcommand{\topicTitle}{27 Specification Via UML (Ch.\ 5 and others)}
 \ifDraft
 \newcommand{\topic}{\topicTitle~DRAFT}
 \else