diff --git a/books11-13.tex b/books11-13.tex
index 90683fb..2948262 100644
--- a/books11-13.tex
+++ b/books11-13.tex
@@ -16,8 +16,7 @@
 	topspace=10mm,
 	footer=0mm]	
 	
-\switchtobodyfont[10pt]
-\setupbodyfont[ebgaramond-be]
+\setupbodyfont[ebgaramond-be,10pt]
 
 \input preamble.tex
 \input preamble_be.tex
diff --git a/byrne.mp b/byrne.mp
index 88d21e8..4023f6a 100644
--- a/byrne.mp
+++ b/byrne.mp
@@ -3115,7 +3115,7 @@ vardef byConstructCompoundAngle (suffix pointA, pointB, pointC) =
         fi;
     endfor;
     if (not isFirst) or (not isLast):
-        errmessage("Can't construct angle: " & angleName);
+        errmessage("Can't construct angle: " & str pointA & str pointB & str pointC);
     fi;
     rv := angleList;
     rv
diff --git a/byrne_context.tex b/byrne_context.tex
index e99b89f..5f5d8b8 100644
--- a/byrne_context.tex
+++ b/byrne_context.tex
@@ -15,9 +15,8 @@
 	headerdistance=8mm,
 	topspace=10mm,
 	footer=0mm]	
-	
-\switchtobodyfont[10pt]
-\setupbodyfont[ebgaramond-be]
+
+\setupbodyfont[ebgaramond-be,10pt]
 
 \input preamble.tex
 \input preamble_be.tex
diff --git a/byrne_ru_context.tex b/byrne_ru_context.tex
index b48756e..e71bfc0 100644
--- a/byrne_ru_context.tex
+++ b/byrne_ru_context.tex
@@ -16,8 +16,7 @@
 	topspace=10mm,
 	footer=0mm]	
 	
-\switchtobodyfont[10pt]
-\setupbodyfont[ebgaramond-be]
+\setupbodyfont[ebgaramond-be,10pt]
 
 \input preamble.tex
 \input preamble_be.tex
diff --git a/preamble_be.tex b/preamble_be.tex
index bbc3a78..e6794bf 100644
--- a/preamble_be.tex
+++ b/preamble_be.tex
@@ -276,16 +276,16 @@
   \startbook[ownnumber={\directconvertedcounter{book}\empty},incrementnumber=no,#1][#2]}
 
 \definehead[supersection][coupling=chapter,default=chapter,incrementnumber=no,placehead=yes,page=no]
-\define[2]\supersectionTitle{\vbox{\ \hfill \tfb #2 \hfill\ }}
-\setuphead[supersection][alternative=text,command=\supersectionTitle,before={\blank[2\baselineskip]},after={}]
+\define[2]\supersectionTitle{\midaligned{\tfb #2}}
+\setuphead[supersection][command=\supersectionTitle,before={\blank[line]},after={\blank[line]}]
 
 \definehead[silentSupersection][coupling=chapter,default=chapter,incrementnumber=no,placehead=yes,page=no]
 \define[2]\noTitle{}
-\setuphead[silentSupersection][alternative=text,command=\noTitle,distance=0pt,before={},after={},inbetween={}]
+\setuphead[silentSupersection][alternative=text,command=\noTitle,before={},after={},inbetween={}]
 
 \definehead[subproposition][subsection]
-\define[2]\subpropositionTitle{\vbox{\ \hfill #2 \hfill\ }}
-\setuphead[subproposition][alternative=text,command=\subpropositionTitle,distance=0pt,before={\blank[\baselineskip]},after={}]
+\define[2]\subpropositionTitle{\midaligned{#2}}
+\setuphead[subproposition][command=\subpropositionTitle,before={\blank[line]},after={\blank[line]}]
 
 %\definehighlight[emph][style=italic]
 \def\emph#1{{\em #1}}
@@ -340,15 +340,15 @@
 
 \definehead[silentsection][section]
 \define[2]\noTitle{}
-\setuphead[silentsection][alternative=text,command=\noTitle,distance=0pt,before={},after={},inbetween={}]
+\setuphead[silentsection][alternative=text,command=\noTitle,before={},after={},inbetween={}]
 
 \definehead[sectiononlyname][section]
-\define[2]\definitionTitle{\vbox{\ \hfill #2 \hfill\ }}
-\setuphead[sectiononlyname][alternative=text,command=\definitionTitle,distance=0pt,before={\blank[0.5\baselineskip]},after={}]
+\define[2]\definitionTitle{\midaligned{#2}}
+\setuphead[sectiononlyname][command=\definitionTitle,number=no,before={\blank[halfline]},after={\blank[halfline]}]
 
 \definehead[sectiononlynumber][section]
-\define[2]\definitionNumber{\vbox{\ \hfill #1 \hfill\ }}
-\setuphead[sectiononlynumber][alternative=text,command=\definitionNumber,distance=0pt,before={\blank[0.5\baselineskip]},after={}]
+\define[2]\definitionNumber{\midaligned{#1}}
+\setuphead[sectiononlynumber][command=\definitionNumber,before={\blank[quarterline]},after={\blank[quarterline]}]
 
 \definecounter[proposition][way=bypart]
 \define\startProposition{\dodoubleempty\startproposition}