diff --git a/runtime/syntax/tex.vim b/runtime/syntax/tex.vim
index d8a384a..7649b27 100644
--- a/runtime/syntax/tex.vim
+++ b/runtime/syntax/tex.vim
@@ -1,9 +1,9 @@
 " Vim syntax file
 " Language:	TeX
 " Maintainer:	Charles E. Campbell <NdrchipO@ScampbellPfamily.AbizM>
-" Last Change:	Nov 14, 2012
-" Version:	75
-" URL:		http://mysite.verizon.net/astronaut/vim/index.html#vimlinks_syntax
+" Last Change:	Mar 11, 2013
+" Version:	77
+" URL:		http://www.drchip.org/astronaut/vim/index.html#SYNTAX_TEX
 "
 " Notes: {{{1
 "
@@ -52,8 +52,14 @@
   command -nargs=+ HiLink hi def link <args>
  endif
 endif
+if exists("g:tex_no_error") && g:tex_no_error
+ let s:tex_no_error= 1
+endif
+if exists("g:tex_fast") && g:tex_fast
+ let s:tex_no_error= 1
+endif
 if exists("g:tex_tex") && !exists("g:tex_no_error")
- let g:tex_no_error= 1
+ let s:tex_no_error= 1
 endif
 
 " let user determine which classes of concealment will be supported
@@ -110,7 +116,7 @@
 " Clusters: {{{1
 " --------
 syn cluster texCmdGroup		contains=texCmdBody,texComment,texDefParm,texDelimiter,texDocType,texInput,texLength,texLigature,texMathDelim,texMathOper,texNewCmd,texNewEnv,texRefZone,texSection,texBeginEnd,texBeginEndName,texSpecialChar,texStatement,texString,texTypeSize,texTypeStyle
-if !exists("g:tex_no_error")
+if !exists("s:tex_no_error")
  syn cluster texCmdGroup	add=texMathError
 endif
 syn cluster texEnvGroup		contains=texMatcher,texMathDelim,texSpecialChar,texStatement
@@ -132,7 +138,7 @@
  syn cluster texMathDelimGroup	contains=texMathDelimBad,texMathDelimKey,texMathDelimSet1,texMathDelimSet2
  syn cluster texMathMatchGroup	contains=@texMathZones,texComment,texDefCmd,texDelimiter,texDocType,texInput,texLength,texLigature,texMathDelim,texMathMatcher,texMathOper,texNewCmd,texNewEnv,texRefZone,texSection,texSpecialChar,texStatement,texString,texTypeSize,texTypeStyle,texZone
  syn cluster texMathZoneGroup	contains=texComment,texDelimiter,texLength,texMathDelim,texMathMatcher,texMathOper,texMathSymbol,texMathText,texRefZone,texSpecialChar,texStatement,texTypeSize,texTypeStyle
- if !exists("g:tex_no_error")
+ if !exists("s:tex_no_error")
   syn cluster texMathMatchGroup	add=texMathError
   syn cluster texMathZoneGroup	add=texMathError
  endif
@@ -153,26 +159,30 @@
 endif
 
 " Try to flag {} and () mismatches: {{{1
-if !exists("g:tex_no_error")
- syn region texMatcher		matchgroup=Delimiter start="{" skip="\\\\\|\\[{}]"	end="}"		contains=@texMatchGroup,texError
- syn region texMatcher		matchgroup=Delimiter start="\["				end="]"		contains=@texMatchGroup,texError,@NoSpell
-else
- syn region texMatcher		matchgroup=Delimiter start="{" skip="\\\\\|\\[{}]"	end="}"		contains=@texMatchGroup
- syn region texMatcher		matchgroup=Delimiter start="\["				end="]"		contains=@texMatchGroup
+if !exists("g:tex_fast") || g:tex_fast =~ 'm'
+  if !exists("s:tex_no_error")
+   syn region texMatcher		matchgroup=Delimiter start="{" skip="\\\\\|\\[{}]"	end="}"		contains=@texMatchGroup,texError
+   syn region texMatcher		matchgroup=Delimiter start="\["				end="]"		contains=@texMatchGroup,texError,@NoSpell
+  else
+   syn region texMatcher		matchgroup=Delimiter start="{" skip="\\\\\|\\[{}]"	end="}"		contains=@texMatchGroup
+   syn region texMatcher		matchgroup=Delimiter start="\["				end="]"		contains=@texMatchGroup
+  endif
+  if !exists("g:tex_nospell") || !g:tex_nospell
+   syn region texParen		start="("						end=")"		contains=@texMatchGroup,@Spell
+  else
+   syn region texParen		start="("						end=")"		contains=@texMatchGroup
+  endif
 endif
-if !exists("g:tex_nospell") || !g:tex_nospell
- syn region texParen		start="("						end=")"		contains=@texMatchGroup,@Spell
-else
- syn region texParen		start="("						end=")"		contains=@texMatchGroup
-endif
-if !exists("g:tex_no_error")
+if !exists("s:tex_no_error")
  syn match  texError		"[}\])]"
 endif
-if !exists("tex_no_math")
- if !exists("g:tex_no_error")
-  syn match  texMathError	"}"	contained
- endif
- syn region texMathMatcher	matchgroup=Delimiter	start="{"          skip="\\\\\|\\}"     end="}" end="%stopzone\>"	contained contains=@texMathMatchGroup
+if !exists("g:tex_fast") || g:tex_fast =~ 'M'
+  if !exists("tex_no_math")
+   if !exists("s:tex_no_error")
+    syn match  texMathError	"}"	contained
+   endif
+   syn region texMathMatcher	matchgroup=Delimiter	start="{"          skip="\\\\\|\\}"     end="}" end="%stopzone\>"	contained contains=@texMathMatchGroup
+  endif
 endif
 
 " TeX/LaTeX keywords: {{{1
@@ -182,7 +192,7 @@
   syn match texStatement	"\\[a-zA-Z@]\+"
 else
   syn match texStatement	"\\\a\+"
-  if !exists("g:tex_no_error")
+  if !exists("s:tex_no_error")
    syn match texError		"\\\a*@[a-zA-Z@]*"
   endif
 endif
@@ -210,12 +220,16 @@
 
 " \begin{}/\end{} section markers: {{{1
 syn match  texBeginEnd		"\\begin\>\|\\end\>" nextgroup=texBeginEndName
-syn region texBeginEndName	matchgroup=Delimiter	start="{"		end="}"	contained	nextgroup=texBeginEndModifier	contains=texComment
-syn region texBeginEndModifier	matchgroup=Delimiter	start="\["		end="]"	contained	contains=texComment,@NoSpell
+if !exists("g:tex_fast") || g:tex_fast =~ 'm'
+  syn region texBeginEndName	matchgroup=Delimiter	start="{"		end="}"	contained	nextgroup=texBeginEndModifier	contains=texComment
+  syn region texBeginEndModifier	matchgroup=Delimiter	start="\["		end="]"	contained	contains=texComment,@NoSpell
+endif
 
 " \documentclass, \documentstyle, \usepackage: {{{1
 syn match  texDocType		"\\documentclass\>\|\\documentstyle\>\|\\usepackage\>"	nextgroup=texBeginEndName,texDocTypeArgs
-syn region texDocTypeArgs	matchgroup=Delimiter start="\[" end="]"			contained	nextgroup=texBeginEndName	contains=texComment,@NoSpell
+if !exists("g:tex_fast") || g:tex_fast =~ 'm'
+  syn region texDocTypeArgs	matchgroup=Delimiter start="\[" end="]"			contained	nextgroup=texBeginEndName	contains=texComment,@NoSpell
+endif
 
 " Preamble syntax-based folding support: {{{1
 if g:tex_fold_enabled && has("folding")
@@ -227,7 +241,9 @@
 syn match texInputFile		"\\include\(graphics\|list\)\=\(\[.\{-}\]\)\=\s*{.\{-}}"	contains=texStatement,texInputCurlies,texInputFileOpt
 syn match texInputFile		"\\\(epsfig\|input\|usepackage\)\s*\(\[.*\]\)\={.\{-}}"		contains=texStatement,texInputCurlies,texInputFileOpt
 syn match texInputCurlies	"[{}]"								contained
-syn region texInputFileOpt	matchgroup=Delimiter start="\[" end="\]"			contained	contains=texComment
+if !exists("g:tex_fast") || g:tex_fast =~ 'm'
+ syn region texInputFileOpt	matchgroup=Delimiter start="\[" end="\]"			contained	contains=texComment
+endif
 
 " Type Styles (LaTeX 2.09): {{{1
 syn match texTypeStyle		"\\rm\>"
@@ -293,62 +309,66 @@
 syn match texSpaceCodeChar    "`\\\=.\(\^.\)\==\(\d\|\"\x\{1,6}\|`.\)"	contained
 
 " Sections, subsections, etc: {{{1
-if !exists("g:tex_nospell") || !g:tex_nospell
- if g:tex_fold_enabled && has("folding")
-  syn region texDocZone			matchgroup=texSection start='\\begin\s*{\s*document\s*}' end='\\end\s*{\s*document\s*}'											fold contains=@texFoldGroup,@texDocGroup,@Spell
-  syn region texPartZone		matchgroup=texSection start='\\part\>'			 end='\ze\s*\\\%(part\>\|end\s*{\s*document\s*}\)'								fold contains=@texFoldGroup,@texPartGroup,@Spell
-  syn region texChapterZone		matchgroup=texSection start='\\chapter\>'		 end='\ze\s*\\\%(chapter\>\|part\>\|end\s*{\s*document\s*}\)'							fold contains=@texFoldGroup,@texChapterGroup,@Spell
-  syn region texSectionZone		matchgroup=texSection start='\\section\>'		 end='\ze\s*\\\%(section\>\|chapter\>\|part\>\|end\s*{\s*document\s*}\)'					fold contains=@texFoldGroup,@texSectionGroup,@Spell
-  syn region texSubSectionZone		matchgroup=texSection start='\\subsection\>'		 end='\ze\s*\\\%(\%(sub\)\=section\>\|chapter\>\|part\>\|end\s*{\s*document\s*}\)'				fold contains=@texFoldGroup,@texSubSectionGroup,@Spell
-  syn region texSubSubSectionZone	matchgroup=texSection start='\\subsubsection\>'		 end='\ze\s*\\\%(\%(sub\)\{,2}section\>\|chapter\>\|part\>\|end\s*{\s*document\s*}\)'				fold contains=@texFoldGroup,@texSubSubSectionGroup,@Spell
-  syn region texParaZone		matchgroup=texSection start='\\paragraph\>'		 end='\ze\s*\\\%(paragraph\>\|\%(sub\)*section\>\|chapter\>\|part\>\|end\s*{\s*document\s*}\)'			fold contains=@texFoldGroup,@texParaGroup,@Spell
-  syn region texSubParaZone		matchgroup=texSection start='\\subparagraph\>'		 end='\ze\s*\\\%(\%(sub\)\=paragraph\>\|\%(sub\)*section\>\|chapter\>\|part\>\|end\s*{\s*document\s*}\)'	fold contains=@texFoldGroup,@Spell
-  syn region texTitle			matchgroup=texSection start='\\\%(author\|title\)\>\s*{' end='}'													fold contains=@texFoldGroup,@Spell
-  syn region texAbstract		matchgroup=texSection start='\\begin\s*{\s*abstract\s*}' end='\\end\s*{\s*abstract\s*}'											fold contains=@texFoldGroup,@Spell
- else
-  syn region texDocZone			matchgroup=texSection start='\\begin\s*{\s*document\s*}' end='\\end\s*{\s*document\s*}'											contains=@texFoldGroup,@texDocGroup,@Spell
-  syn region texPartZone		matchgroup=texSection start='\\part\>'			 end='\ze\s*\\\%(part\>\|end\s*{\s*document\s*}\)'								contains=@texFoldGroup,@texPartGroup,@Spell
-  syn region texChapterZone		matchgroup=texSection start='\\chapter\>'		 end='\ze\s*\\\%(chapter\>\|part\>\|end\s*{\s*document\s*}\)'							contains=@texFoldGroup,@texChapterGroup,@Spell
-  syn region texSectionZone		matchgroup=texSection start='\\section\>'		 end='\ze\s*\\\%(section\>\|chapter\>\|part\>\|end\s*{\s*document\s*}\)'					contains=@texFoldGroup,@texSectionGroup,@Spell
-  syn region texSubSectionZone		matchgroup=texSection start='\\subsection\>'		 end='\ze\s*\\\%(\%(sub\)\=section\>\|chapter\>\|part\>\|end\s*{\s*document\s*}\)'				contains=@texFoldGroup,@texSubSectionGroup,@Spell
-  syn region texSubSubSectionZone	matchgroup=texSection start='\\subsubsection\>'		 end='\ze\s*\\\%(\%(sub\)\{,2}section\>\|chapter\>\|part\>\|end\s*{\s*document\s*}\)'				contains=@texFoldGroup,@texSubSubSectionGroup,@Spell
-  syn region texParaZone		matchgroup=texSection start='\\paragraph\>'		 end='\ze\s*\\\%(paragraph\>\|\%(sub\)*section\>\|chapter\>\|part\>\|end\s*{\s*document\s*}\)'			contains=@texFoldGroup,@texParaGroup,@Spell
-  syn region texSubParaZone		matchgroup=texSection start='\\subparagraph\>'		 end='\ze\s*\\\%(\%(sub\)\=paragraph\>\|\%(sub\)*section\>\|chapter\>\|part\>\|end\s*{\s*document\s*}\)'	contains=@texFoldGroup,@Spell
-  syn region texTitle			matchgroup=texSection start='\\\%(author\|title\)\>\s*{' end='}'													contains=@texFoldGroup,@Spell
-  syn region texAbstract		matchgroup=texSection start='\\begin\s*{\s*abstract\s*}' end='\\end\s*{\s*abstract\s*}'											contains=@texFoldGroup,@Spell
- endif
-else
- if g:tex_fold_enabled && has("folding")
-  syn region texDocZone			matchgroup=texSection start='\\begin\s*{\s*document\s*}' end='\\end\s*{\s*document\s*}'											fold contains=@texFoldGroup,@texDocGroup
-  syn region texPartZone		matchgroup=texSection start='\\part\>'			 end='\ze\s*\\\%(part\>\|end\s*{\s*document\s*}\)'								fold contains=@texFoldGroup,@texPartGroup
-  syn region texChapterZone		matchgroup=texSection start='\\chapter\>'		 end='\ze\s*\\\%(chapter\>\|part\>\|end\s*{\s*document\s*}\)'							fold contains=@texFoldGroup,@texChapterGroup
-  syn region texSectionZone		matchgroup=texSection start='\\section\>'		 end='\ze\s*\\\%(section\>\|chapter\>\|part\>\|end\s*{\s*document\s*}\)'					fold contains=@texFoldGroup,@texSectionGroup
-  syn region texSubSectionZone		matchgroup=texSection start='\\subsection\>'		 end='\ze\s*\\\%(\%(sub\)\=section\>\|chapter\>\|part\>\|end\s*{\s*document\s*}\)'				fold contains=@texFoldGroup,@texSubSectionGroup
-  syn region texSubSubSectionZone	matchgroup=texSection start='\\subsubsection\>'		 end='\ze\s*\\\%(\%(sub\)\{,2}section\>\|chapter\>\|part\>\|end\s*{\s*document\s*}\)'				fold contains=@texFoldGroup,@texSubSubSectionGroup
-  syn region texParaZone		matchgroup=texSection start='\\paragraph\>'		 end='\ze\s*\\\%(paragraph\>\|\%(sub\)*section\>\|chapter\>\|part\>\|end\s*{\s*document\s*}\)'			fold contains=@texFoldGroup,@texParaGroup
-  syn region texSubParaZone		matchgroup=texSection start='\\subparagraph\>'		 end='\ze\s*\\\%(\%(sub\)\=paragraph\>\|\%(sub\)*section\>\|chapter\>\|part\>\|end\s*{\s*document\s*}\)'	fold contains=@texFoldGroup
-  syn region texTitle			matchgroup=texSection start='\\\%(author\|title\)\>\s*{' end='}'													fold contains=@texFoldGroup
-  syn region texAbstract		matchgroup=texSection start='\\begin\s*{\s*abstract\s*}' end='\\end\s*{\s*abstract\s*}'											fold contains=@texFoldGroup
- else
-  syn region texDocZone			matchgroup=texSection start='\\begin\s*{\s*document\s*}' end='\\end\s*{\s*document\s*}'											contains=@texFoldGroup,@texDocGroup
-  syn region texPartZone		matchgroup=texSection start='\\part\>'			 end='\ze\s*\\\%(part\>\|end\s*{\s*document\s*}\)'								contains=@texFoldGroup,@texPartGroup
-  syn region texChapterZone		matchgroup=texSection start='\\chapter\>'		 end='\ze\s*\\\%(chapter\>\|part\>\|end\s*{\s*document\s*}\)'							contains=@texFoldGroup,@texChapterGroup
-  syn region texSectionZone		matchgroup=texSection start='\\section\>'		 end='\ze\s*\\\%(section\>\|chapter\>\|part\>\|end\s*{\s*document\s*}\)'					contains=@texFoldGroup,@texSectionGroup
-  syn region texSubSectionZone		matchgroup=texSection start='\\subsection\>'		 end='\ze\s*\\\%(\%(sub\)\=section\>\|chapter\>\|part\>\|end\s*{\s*document\s*}\)'				contains=@texFoldGroup,@texSubSectionGroup
-  syn region texSubSubSectionZone	matchgroup=texSection start='\\subsubsection\>'		 end='\ze\s*\\\%(\%(sub\)\{,2}section\>\|chapter\>\|part\>\|end\s*{\s*document\s*}\)'				contains=@texFoldGroup,@texSubSubSectionGroup
-  syn region texParaZone		matchgroup=texSection start='\\paragraph\>'		 end='\ze\s*\\\%(paragraph\>\|\%(sub\)*section\>\|chapter\>\|part\>\|end\s*{\s*document\s*}\)'			contains=@texFoldGroup,@texParaGroup
-  syn region texSubParaZone		matchgroup=texSection start='\\subparagraph\>'		 end='\ze\s*\\\%(\%(sub\)\=paragraph\>\|\%(sub\)*section\>\|chapter\>\|part\>\|end\s*{\s*document\s*}\)'	contains=@texFoldGroup
-  syn region texTitle			matchgroup=texSection start='\\\%(author\|title\)\>\s*{' end='}'													contains=@texFoldGroup
-  syn region texAbstract		matchgroup=texSection start='\\begin\s*{\s*abstract\s*}' end='\\end\s*{\s*abstract\s*}'											contains=@texFoldGroup
- endif
+if !exists("g:tex_fast") || g:tex_fast =~ 'p'
+  if !exists("g:tex_nospell") || !g:tex_nospell
+   if g:tex_fold_enabled && has("folding")
+    syn region texDocZone			matchgroup=texSection start='\\begin\s*{\s*document\s*}' end='\\end\s*{\s*document\s*}'											fold contains=@texFoldGroup,@texDocGroup,@Spell
+    syn region texPartZone		matchgroup=texSection start='\\part\>'			 end='\ze\s*\\\%(part\>\|end\s*{\s*document\s*}\)'								fold contains=@texFoldGroup,@texPartGroup,@Spell
+    syn region texChapterZone		matchgroup=texSection start='\\chapter\>'		 end='\ze\s*\\\%(chapter\>\|part\>\|end\s*{\s*document\s*}\)'							fold contains=@texFoldGroup,@texChapterGroup,@Spell
+    syn region texSectionZone		matchgroup=texSection start='\\section\>'		 end='\ze\s*\\\%(section\>\|chapter\>\|part\>\|end\s*{\s*document\s*}\)'					fold contains=@texFoldGroup,@texSectionGroup,@Spell
+    syn region texSubSectionZone		matchgroup=texSection start='\\subsection\>'		 end='\ze\s*\\\%(\%(sub\)\=section\>\|chapter\>\|part\>\|end\s*{\s*document\s*}\)'				fold contains=@texFoldGroup,@texSubSectionGroup,@Spell
+    syn region texSubSubSectionZone	matchgroup=texSection start='\\subsubsection\>'		 end='\ze\s*\\\%(\%(sub\)\{,2}section\>\|chapter\>\|part\>\|end\s*{\s*document\s*}\)'				fold contains=@texFoldGroup,@texSubSubSectionGroup,@Spell
+    syn region texParaZone		matchgroup=texSection start='\\paragraph\>'		 end='\ze\s*\\\%(paragraph\>\|\%(sub\)*section\>\|chapter\>\|part\>\|end\s*{\s*document\s*}\)'			fold contains=@texFoldGroup,@texParaGroup,@Spell
+    syn region texSubParaZone		matchgroup=texSection start='\\subparagraph\>'		 end='\ze\s*\\\%(\%(sub\)\=paragraph\>\|\%(sub\)*section\>\|chapter\>\|part\>\|end\s*{\s*document\s*}\)'	fold contains=@texFoldGroup,@Spell
+    syn region texTitle			matchgroup=texSection start='\\\%(author\|title\)\>\s*{' end='}'													fold contains=@texFoldGroup,@Spell
+    syn region texAbstract		matchgroup=texSection start='\\begin\s*{\s*abstract\s*}' end='\\end\s*{\s*abstract\s*}'											fold contains=@texFoldGroup,@Spell
+   else
+    syn region texDocZone			matchgroup=texSection start='\\begin\s*{\s*document\s*}' end='\\end\s*{\s*document\s*}'											contains=@texFoldGroup,@texDocGroup,@Spell
+    syn region texPartZone		matchgroup=texSection start='\\part\>'			 end='\ze\s*\\\%(part\>\|end\s*{\s*document\s*}\)'								contains=@texFoldGroup,@texPartGroup,@Spell
+    syn region texChapterZone		matchgroup=texSection start='\\chapter\>'		 end='\ze\s*\\\%(chapter\>\|part\>\|end\s*{\s*document\s*}\)'							contains=@texFoldGroup,@texChapterGroup,@Spell
+    syn region texSectionZone		matchgroup=texSection start='\\section\>'		 end='\ze\s*\\\%(section\>\|chapter\>\|part\>\|end\s*{\s*document\s*}\)'					contains=@texFoldGroup,@texSectionGroup,@Spell
+    syn region texSubSectionZone		matchgroup=texSection start='\\subsection\>'		 end='\ze\s*\\\%(\%(sub\)\=section\>\|chapter\>\|part\>\|end\s*{\s*document\s*}\)'				contains=@texFoldGroup,@texSubSectionGroup,@Spell
+    syn region texSubSubSectionZone	matchgroup=texSection start='\\subsubsection\>'		 end='\ze\s*\\\%(\%(sub\)\{,2}section\>\|chapter\>\|part\>\|end\s*{\s*document\s*}\)'				contains=@texFoldGroup,@texSubSubSectionGroup,@Spell
+    syn region texParaZone		matchgroup=texSection start='\\paragraph\>'		 end='\ze\s*\\\%(paragraph\>\|\%(sub\)*section\>\|chapter\>\|part\>\|end\s*{\s*document\s*}\)'			contains=@texFoldGroup,@texParaGroup,@Spell
+    syn region texSubParaZone		matchgroup=texSection start='\\subparagraph\>'		 end='\ze\s*\\\%(\%(sub\)\=paragraph\>\|\%(sub\)*section\>\|chapter\>\|part\>\|end\s*{\s*document\s*}\)'	contains=@texFoldGroup,@Spell
+    syn region texTitle			matchgroup=texSection start='\\\%(author\|title\)\>\s*{' end='}'													contains=@texFoldGroup,@Spell
+    syn region texAbstract		matchgroup=texSection start='\\begin\s*{\s*abstract\s*}' end='\\end\s*{\s*abstract\s*}'											contains=@texFoldGroup,@Spell
+   endif
+  else
+   if g:tex_fold_enabled && has("folding")
+    syn region texDocZone			matchgroup=texSection start='\\begin\s*{\s*document\s*}' end='\\end\s*{\s*document\s*}'											fold contains=@texFoldGroup,@texDocGroup
+    syn region texPartZone		matchgroup=texSection start='\\part\>'			 end='\ze\s*\\\%(part\>\|end\s*{\s*document\s*}\)'								fold contains=@texFoldGroup,@texPartGroup
+    syn region texChapterZone		matchgroup=texSection start='\\chapter\>'		 end='\ze\s*\\\%(chapter\>\|part\>\|end\s*{\s*document\s*}\)'							fold contains=@texFoldGroup,@texChapterGroup
+    syn region texSectionZone		matchgroup=texSection start='\\section\>'		 end='\ze\s*\\\%(section\>\|chapter\>\|part\>\|end\s*{\s*document\s*}\)'					fold contains=@texFoldGroup,@texSectionGroup
+    syn region texSubSectionZone		matchgroup=texSection start='\\subsection\>'		 end='\ze\s*\\\%(\%(sub\)\=section\>\|chapter\>\|part\>\|end\s*{\s*document\s*}\)'				fold contains=@texFoldGroup,@texSubSectionGroup
+    syn region texSubSubSectionZone	matchgroup=texSection start='\\subsubsection\>'		 end='\ze\s*\\\%(\%(sub\)\{,2}section\>\|chapter\>\|part\>\|end\s*{\s*document\s*}\)'				fold contains=@texFoldGroup,@texSubSubSectionGroup
+    syn region texParaZone		matchgroup=texSection start='\\paragraph\>'		 end='\ze\s*\\\%(paragraph\>\|\%(sub\)*section\>\|chapter\>\|part\>\|end\s*{\s*document\s*}\)'			fold contains=@texFoldGroup,@texParaGroup
+    syn region texSubParaZone		matchgroup=texSection start='\\subparagraph\>'		 end='\ze\s*\\\%(\%(sub\)\=paragraph\>\|\%(sub\)*section\>\|chapter\>\|part\>\|end\s*{\s*document\s*}\)'	fold contains=@texFoldGroup
+    syn region texTitle			matchgroup=texSection start='\\\%(author\|title\)\>\s*{' end='}'													fold contains=@texFoldGroup
+    syn region texAbstract		matchgroup=texSection start='\\begin\s*{\s*abstract\s*}' end='\\end\s*{\s*abstract\s*}'											fold contains=@texFoldGroup
+   else
+    syn region texDocZone			matchgroup=texSection start='\\begin\s*{\s*document\s*}' end='\\end\s*{\s*document\s*}'											contains=@texFoldGroup,@texDocGroup
+    syn region texPartZone		matchgroup=texSection start='\\part\>'			 end='\ze\s*\\\%(part\>\|end\s*{\s*document\s*}\)'								contains=@texFoldGroup,@texPartGroup
+    syn region texChapterZone		matchgroup=texSection start='\\chapter\>'		 end='\ze\s*\\\%(chapter\>\|part\>\|end\s*{\s*document\s*}\)'							contains=@texFoldGroup,@texChapterGroup
+    syn region texSectionZone		matchgroup=texSection start='\\section\>'		 end='\ze\s*\\\%(section\>\|chapter\>\|part\>\|end\s*{\s*document\s*}\)'					contains=@texFoldGroup,@texSectionGroup
+    syn region texSubSectionZone		matchgroup=texSection start='\\subsection\>'		 end='\ze\s*\\\%(\%(sub\)\=section\>\|chapter\>\|part\>\|end\s*{\s*document\s*}\)'				contains=@texFoldGroup,@texSubSectionGroup
+    syn region texSubSubSectionZone	matchgroup=texSection start='\\subsubsection\>'		 end='\ze\s*\\\%(\%(sub\)\{,2}section\>\|chapter\>\|part\>\|end\s*{\s*document\s*}\)'				contains=@texFoldGroup,@texSubSubSectionGroup
+    syn region texParaZone		matchgroup=texSection start='\\paragraph\>'		 end='\ze\s*\\\%(paragraph\>\|\%(sub\)*section\>\|chapter\>\|part\>\|end\s*{\s*document\s*}\)'			contains=@texFoldGroup,@texParaGroup
+    syn region texSubParaZone		matchgroup=texSection start='\\subparagraph\>'		 end='\ze\s*\\\%(\%(sub\)\=paragraph\>\|\%(sub\)*section\>\|chapter\>\|part\>\|end\s*{\s*document\s*}\)'	contains=@texFoldGroup
+    syn region texTitle			matchgroup=texSection start='\\\%(author\|title\)\>\s*{' end='}'													contains=@texFoldGroup
+    syn region texAbstract		matchgroup=texSection start='\\begin\s*{\s*abstract\s*}' end='\\end\s*{\s*abstract\s*}'											contains=@texFoldGroup
+   endif
+  endif
 endif
 
 " particular support for bold and italic {{{1
-if s:tex_conceal =~ 'b'
- syn region texBoldStyle	matchgroup=texTypeStyle start="\\textbf\s*{" end="}" concealends contains=@texBoldGroup
- syn region texBoldItalStyle	matchgroup=texTypeStyle start="\\textit\s*{" end="}" concealends contains=@texItalGroup
- syn region texItalStyle	matchgroup=texTypeStyle start="\\textit\s*{" end="}" concealends contains=@texItalGroup
- syn region texItalBoldStyle	matchgroup=texTypeStyle start="\\textbf\s*{" end="}" concealends contains=@texBoldGroup
+if !exists("g:tex_fast") || g:tex_fast =~ 'b'
+  if s:tex_conceal =~ 'b'
+   syn region texBoldStyle	matchgroup=texTypeStyle start="\\textbf\s*{" end="}" concealends contains=@texBoldGroup
+   syn region texBoldItalStyle	matchgroup=texTypeStyle start="\\textit\s*{" end="}" concealends contains=@texItalGroup
+   syn region texItalStyle	matchgroup=texTypeStyle start="\\textit\s*{" end="}" concealends contains=@texItalGroup
+   syn region texItalBoldStyle	matchgroup=texTypeStyle start="\\textbf\s*{" end="}" concealends contains=@texBoldGroup
+  endif
 endif
 
 " Bad Math (mismatched): {{{1
@@ -373,17 +393,21 @@
     let foldcmd= ""
    endif
    exe "syn cluster texMathZones add=".grpname
-   exe 'syn region '.grpname.' start='."'".'\\begin\s*{\s*'.a:mathzone.'\s*}'."'".' end='."'".'\\end\s*{\s*'.a:mathzone.'\s*}'."'".' keepend contains=@texMathZoneGroup'.foldcmd
-   exe 'syn sync match '.syncname.' grouphere '.grpname.' "\\begin\s*{\s*'.a:mathzone.'\*\s*}"'
-   exe 'syn sync match '.syncname.' grouphere '.grpname.' "\\begin\s*{\s*'.a:mathzone.'\*\s*}"'
+   if !exists("g:tex_fast") || g:tex_fast =~ 'M'
+    exe 'syn region '.grpname.' start='."'".'\\begin\s*{\s*'.a:mathzone.'\s*}'."'".' end='."'".'\\end\s*{\s*'.a:mathzone.'\s*}'."'".' keepend contains=@texMathZoneGroup'.foldcmd
+    exe 'syn sync match '.syncname.' grouphere '.grpname.' "\\begin\s*{\s*'.a:mathzone.'\*\s*}"'
+    exe 'syn sync match '.syncname.' grouphere '.grpname.' "\\begin\s*{\s*'.a:mathzone.'\*\s*}"'
+   endif
    exe 'hi def link '.grpname.' texMath'
    if a:starform
     let grpname  = "texMathZone".a:sfx.'S'
     let syncname = "texSyncMathZone".a:sfx.'S'
     exe "syn cluster texMathZones add=".grpname
-    exe 'syn region '.grpname.' start='."'".'\\begin\s*{\s*'.a:mathzone.'\*\s*}'."'".' end='."'".'\\end\s*{\s*'.a:mathzone.'\*\s*}'."'".' keepend contains=@texMathZoneGroup'.foldcmd
-    exe 'syn sync match '.syncname.' grouphere '.grpname.' "\\begin\s*{\s*'.a:mathzone.'\*\s*}"'
-    exe 'syn sync match '.syncname.' grouphere '.grpname.' "\\begin\s*{\s*'.a:mathzone.'\*\s*}"'
+    if !exists("g:tex_fast") || g:tex_fast =~ 'M'
+     exe 'syn region '.grpname.' start='."'".'\\begin\s*{\s*'.a:mathzone.'\*\s*}'."'".' end='."'".'\\end\s*{\s*'.a:mathzone.'\*\s*}'."'".' keepend contains=@texMathZoneGroup'.foldcmd
+     exe 'syn sync match '.syncname.' grouphere '.grpname.' "\\begin\s*{\s*'.a:mathzone.'\*\s*}"'
+     exe 'syn sync match '.syncname.' grouphere '.grpname.' "\\begin\s*{\s*'.a:mathzone.'\*\s*}"'
+    endif
     exe 'hi def link '.grpname.' texMath'
    endif
  endfun
@@ -403,26 +427,30 @@
  call TexNewMathZone("L","xxalignat",0)
 
  " Inline Math Zones: {{{2
- if has("conceal") && &enc == 'utf-8' && s:tex_conceal =~ 'd'
-  syn region texMathZoneV	matchgroup=Delimiter start="\\("			matchgroup=Delimiter end="\\)\|%stopzone\>"	keepend concealends contains=@texMathZoneGroup
-  syn region texMathZoneW	matchgroup=Delimiter start="\\\["			matchgroup=Delimiter end="\\]\|%stopzone\>"	keepend concealends contains=@texMathZoneGroup
-  syn region texMathZoneX	matchgroup=Delimiter start="\$" skip="\\\\\|\\\$"	matchgroup=Delimiter end="\$" end="%stopzone\>"		concealends contains=@texMathZoneGroup
-  syn region texMathZoneY	matchgroup=Delimiter start="\$\$" 			matchgroup=Delimiter end="\$\$" end="%stopzone\>"	concealends keepend		contains=@texMathZoneGroup
- else
-  syn region texMathZoneV	matchgroup=Delimiter start="\\("			matchgroup=Delimiter end="\\)\|%stopzone\>"	keepend contains=@texMathZoneGroup
-  syn region texMathZoneW	matchgroup=Delimiter start="\\\["			matchgroup=Delimiter end="\\]\|%stopzone\>"	keepend contains=@texMathZoneGroup
-  syn region texMathZoneX	matchgroup=Delimiter start="\$" skip="\\\\\|\\\$"	matchgroup=Delimiter end="\$" end="%stopzone\>"	contains=@texMathZoneGroup
-  syn region texMathZoneY	matchgroup=Delimiter start="\$\$" 			matchgroup=Delimiter end="\$\$" end="%stopzone\>"	keepend		contains=@texMathZoneGroup
+ if !exists("g:tex_fast") || g:tex_fast =~ 'M'
+  if has("conceal") && &enc == 'utf-8' && s:tex_conceal =~ 'd'
+   syn region texMathZoneV	matchgroup=Delimiter start="\\("			matchgroup=Delimiter end="\\)\|%stopzone\>"	keepend concealends contains=@texMathZoneGroup
+   syn region texMathZoneW	matchgroup=Delimiter start="\\\["			matchgroup=Delimiter end="\\]\|%stopzone\>"	keepend concealends contains=@texMathZoneGroup
+   syn region texMathZoneX	matchgroup=Delimiter start="\$" skip="\\\\\|\\\$"	matchgroup=Delimiter end="\$" end="%stopzone\>"		concealends contains=@texMathZoneGroup
+   syn region texMathZoneY	matchgroup=Delimiter start="\$\$" 			matchgroup=Delimiter end="\$\$" end="%stopzone\>"	concealends keepend		contains=@texMathZoneGroup
+  else
+   syn region texMathZoneV	matchgroup=Delimiter start="\\("			matchgroup=Delimiter end="\\)\|%stopzone\>"	keepend contains=@texMathZoneGroup
+   syn region texMathZoneW	matchgroup=Delimiter start="\\\["			matchgroup=Delimiter end="\\]\|%stopzone\>"	keepend contains=@texMathZoneGroup
+   syn region texMathZoneX	matchgroup=Delimiter start="\$" skip="\\\\\|\\\$"	matchgroup=Delimiter end="\$" end="%stopzone\>"	contains=@texMathZoneGroup
+   syn region texMathZoneY	matchgroup=Delimiter start="\$\$" 			matchgroup=Delimiter end="\$\$" end="%stopzone\>"	keepend		contains=@texMathZoneGroup
+  endif
+  syn region texMathZoneZ	matchgroup=texStatement start="\\ensuremath\s*{"	matchgroup=texStatement end="}" end="%stopzone\>"	contains=@texMathZoneGroup
  endif
- syn region texMathZoneZ	matchgroup=texStatement start="\\ensuremath\s*{"	matchgroup=texStatement end="}" end="%stopzone\>"	contains=@texMathZoneGroup
 
  syn match texMathOper		"[_^=]" contained
 
  " Text Inside Math Zones: {{{2
- if !exists("g:tex_nospell") || !g:tex_nospell
-  syn region texMathText matchgroup=texStatement start='\\\(\(inter\)\=text\|mbox\)\s*{'	end='}'	contains=@texFoldGroup,@Spell
- else
-  syn region texMathText matchgroup=texStatement start='\\\(\(inter\)\=text\|mbox\)\s*{'	end='}'	contains=@texFoldGroup
+ if !exists("g:tex_fast") || g:tex_fast =~ 'M'
+  if !exists("g:tex_nospell") || !g:tex_nospell
+   syn region texMathText matchgroup=texStatement start='\\\(\(inter\)\=text\|mbox\)\s*{'	end='}'	contains=@texFoldGroup,@Spell
+  else
+   syn region texMathText matchgroup=texStatement start='\\\(\(inter\)\=text\|mbox\)\s*{'	end='}'	contains=@texFoldGroup
+  endif
  endif
 
  " \left..something.. and \right..something.. support: {{{2
@@ -512,65 +540,77 @@
    " allows syntax-folding of 2 or more contiguous comment lines
    " single-line comments are not folded
    syn match  texComment	"%.*$"			contains=@texCommentGroup
-   syn region texComment	start="^\zs\s*%.*\_s*%"	skip="^\s*%"	end='^\ze\s*[^%]' fold
-   syn region texNoSpell	contained fold		matchgroup=texComment start="%\s*nospell\s*{"	end="%\s*nospell\s*}"	contains=@texFoldGroup,@NoSpell
+   if !exists("g:tex_fast") || g:tex_fast =~ 'c'
+    syn region texComment	start="^\zs\s*%.*\_s*%"	skip="^\s*%"	end='^\ze\s*[^%]' fold
+    syn region texNoSpell	contained fold		matchgroup=texComment start="%\s*nospell\s*{"	end="%\s*nospell\s*}"	contains=@texFoldGroup,@NoSpell
+   endif
   else
    syn match texComment		"%.*$"			contains=@texCommentGroup
-   syn region texNoSpell	contained		matchgroup=texComment start="%\s*nospell\s*{"	end="%\s*nospell\s*}"	contains=@texFoldGroup,@NoSpell
+   if !exists("g:tex_fast") || g:tex_fast =~ 'c'
+    syn region texNoSpell	contained		matchgroup=texComment start="%\s*nospell\s*{"	end="%\s*nospell\s*}"	contains=@texFoldGroup,@NoSpell
+   endif
   endif
 endif
 
 " Separate lines used for verb` and verb# so that the end conditions {{{1
 " will appropriately terminate.
 " If g:tex_verbspell exists, then verbatim texZones will permit spellchecking there.
-if exists("g:tex_verbspell") && g:tex_verbspell
- syn region texZone		start="\\begin{[vV]erbatim}"		end="\\end{[vV]erbatim}\|%stopzone\>"	contains=@Spell
- " listings package:
- syn region texZone		start="\\begin{lstlisting}"		end="\\end{lstlisting}\|%stopzone\>"	contains=@Spell
- if version < 600
-  syn region texZone		start="\\verb\*\=`"			end="`\|%stopzone\>"			contains=@Spell
-  syn region texZone		start="\\verb\*\=#"			end="#\|%stopzone\>"			contains=@Spell
- else
-   if b:tex_stylish
-    syn region texZone		start="\\verb\*\=\z([^\ta-zA-Z@]\)"	end="\z1\|%stopzone\>"			contains=@Spell
+if !exists("g:tex_fast") || g:tex_fast =~ 'v'
+  if exists("g:tex_verbspell") && g:tex_verbspell
+   syn region texZone		start="\\begin{[vV]erbatim}"		end="\\end{[vV]erbatim}\|%stopzone\>"	contains=@Spell
+   " listings package:
+   syn region texZone		start="\\begin{lstlisting}"		end="\\end{lstlisting}\|%stopzone\>"	contains=@Spell
+   if version < 600
+    syn region texZone		start="\\verb\*\=`"			end="`\|%stopzone\>"			contains=@Spell
+    syn region texZone		start="\\verb\*\=#"			end="#\|%stopzone\>"			contains=@Spell
    else
-    syn region texZone		start="\\verb\*\=\z([^\ta-zA-Z]\)"	end="\z1\|%stopzone\>"			contains=@Spell
+     if b:tex_stylish
+      syn region texZone		start="\\verb\*\=\z([^\ta-zA-Z@]\)"	end="\z1\|%stopzone\>"			contains=@Spell
+     else
+      syn region texZone		start="\\verb\*\=\z([^\ta-zA-Z]\)"	end="\z1\|%stopzone\>"			contains=@Spell
+     endif
    endif
- endif
-else
- syn region texZone		start="\\begin{[vV]erbatim}"		end="\\end{[vV]erbatim}\|%stopzone\>"
- if version < 600
-  syn region texZone		start="\\verb\*\=`"			end="`\|%stopzone\>"
-  syn region texZone		start="\\verb\*\=#"			end="#\|%stopzone\>"
- else
-   if b:tex_stylish
-     syn region texZone		start="\\verb\*\=\z([^\ta-zA-Z@]\)"	end="\z1\|%stopzone\>"
+  else
+   syn region texZone		start="\\begin{[vV]erbatim}"		end="\\end{[vV]erbatim}\|%stopzone\>"
+   if version < 600
+    syn region texZone		start="\\verb\*\=`"			end="`\|%stopzone\>"
+    syn region texZone		start="\\verb\*\=#"			end="#\|%stopzone\>"
    else
-     syn region texZone		start="\\verb\*\=\z([^\ta-zA-Z]\)"	end="\z1\|%stopzone\>"
+     if b:tex_stylish
+       syn region texZone		start="\\verb\*\=\z([^\ta-zA-Z@]\)"	end="\z1\|%stopzone\>"
+     else
+       syn region texZone		start="\\verb\*\=\z([^\ta-zA-Z]\)"	end="\z1\|%stopzone\>"
+     endif
    endif
- endif
+  endif
 endif
 
 " Tex Reference Zones: {{{1
-syn region texZone		matchgroup=texStatement start="@samp{"			end="}\|%stopzone\>"	contains=@texRefGroup
-syn region texRefZone		matchgroup=texStatement start="\\nocite{"		end="}\|%stopzone\>"	contains=@texRefGroup
-syn region texRefZone		matchgroup=texStatement start="\\bibliography{"		end="}\|%stopzone\>"	contains=@texRefGroup
-syn region texRefZone		matchgroup=texStatement start="\\label{"		end="}\|%stopzone\>"	contains=@texRefGroup
-syn region texRefZone		matchgroup=texStatement start="\\\(page\|eq\)ref{"	end="}\|%stopzone\>"	contains=@texRefGroup
-syn region texRefZone		matchgroup=texStatement start="\\v\=ref{"		end="}\|%stopzone\>"	contains=@texRefGroup
+if !exists("g:tex_fast") || g:tex_fast =~ 'r'
+  syn region texZone		matchgroup=texStatement start="@samp{"			end="}\|%stopzone\>"	contains=@texRefGroup
+  syn region texRefZone		matchgroup=texStatement start="\\nocite{"		end="}\|%stopzone\>"	contains=@texRefGroup
+  syn region texRefZone		matchgroup=texStatement start="\\bibliography{"		end="}\|%stopzone\>"	contains=@texRefGroup
+  syn region texRefZone		matchgroup=texStatement start="\\label{"		end="}\|%stopzone\>"	contains=@texRefGroup
+  syn region texRefZone		matchgroup=texStatement start="\\\(page\|eq\)ref{"	end="}\|%stopzone\>"	contains=@texRefGroup
+  syn region texRefZone		matchgroup=texStatement start="\\v\=ref{"		end="}\|%stopzone\>"	contains=@texRefGroup
+  syn region texRefOption	contained	matchgroup=Delimiter start='\[' end=']'		contains=@texRefGroup,texRefZone	nextgroup=texRefOption,texCite
+  syn region texCite	contained	matchgroup=Delimiter start='{' end='}'		contains=@texRefGroup,texRefZone,texCite
+endif
 syn match  texRefZone		'\\cite\%([tp]\*\=\)\=' nextgroup=texRefOption,texCite
-syn region texRefOption	contained	matchgroup=Delimiter start='\[' end=']'		contains=@texRefGroup,texRefZone	nextgroup=texRefOption,texCite
-syn region texCite	contained	matchgroup=Delimiter start='{' end='}'		contains=@texRefGroup,texRefZone,texCite
 
 " Handle newcommand, newenvironment : {{{1
 syn match  texNewCmd				"\\newcommand\>"			nextgroup=texCmdName skipwhite skipnl
-syn region texCmdName contained matchgroup=Delimiter start="{"rs=s+1  end="}"		nextgroup=texCmdArgs,texCmdBody skipwhite skipnl
-syn region texCmdArgs contained matchgroup=Delimiter start="\["rs=s+1 end="]"		nextgroup=texCmdBody skipwhite skipnl
-syn region texCmdBody contained matchgroup=Delimiter start="{"rs=s+1 skip="\\\\\|\\[{}]"	matchgroup=Delimiter end="}" contains=@texCmdGroup
+if !exists("g:tex_fast") || g:tex_fast =~ 'V'
+  syn region texCmdName contained matchgroup=Delimiter start="{"rs=s+1  end="}"		nextgroup=texCmdArgs,texCmdBody skipwhite skipnl
+  syn region texCmdArgs contained matchgroup=Delimiter start="\["rs=s+1 end="]"		nextgroup=texCmdBody skipwhite skipnl
+  syn region texCmdBody contained matchgroup=Delimiter start="{"rs=s+1 skip="\\\\\|\\[{}]"	matchgroup=Delimiter end="}" contains=@texCmdGroup
+endif
 syn match  texNewEnv				"\\newenvironment\>"			nextgroup=texEnvName skipwhite skipnl
-syn region texEnvName contained matchgroup=Delimiter start="{"rs=s+1  end="}"		nextgroup=texEnvBgn skipwhite skipnl
-syn region texEnvBgn  contained matchgroup=Delimiter start="{"rs=s+1  end="}"		nextgroup=texEnvEnd skipwhite skipnl contains=@texEnvGroup
-syn region texEnvEnd  contained matchgroup=Delimiter start="{"rs=s+1  end="}"		skipwhite skipnl contains=@texEnvGroup
+if !exists("g:tex_fast") || g:tex_fast =~ 'V'
+  syn region texEnvName contained matchgroup=Delimiter start="{"rs=s+1  end="}"		nextgroup=texEnvBgn skipwhite skipnl
+  syn region texEnvBgn  contained matchgroup=Delimiter start="{"rs=s+1  end="}"		nextgroup=texEnvEnd skipwhite skipnl contains=@texEnvGroup
+  syn region texEnvEnd  contained matchgroup=Delimiter start="{"rs=s+1  end="}"		skipwhite skipnl contains=@texEnvGroup
+endif
 
 " Definitions/Commands: {{{1
 syn match texDefCmd				"\\def\>"				nextgroup=texDefName skipwhite skipnl
@@ -591,11 +631,15 @@
 syn match texString		"\(``\|''\|,,\)"
 
 " makeatletter -- makeatother sections
-if !exists("g:tex_no_error")
- syn region texStyle			matchgroup=texStatement start='\\makeatletter' end='\\makeatother'	contains=@texStyleGroup contained
+if !exists("s:tex_no_error")
+ if !exists("g:tex_fast") || g:tex_fast =~ 'S'
+  syn region texStyle			matchgroup=texStatement start='\\makeatletter' end='\\makeatother'	contains=@texStyleGroup contained
+ endif
  syn match  texStyleStatement		"\\[a-zA-Z@]\+"	contained
- syn region texStyleMatcher		matchgroup=Delimiter start="{" skip="\\\\\|\\[{}]"	end="}"		contains=@texStyleGroup,texError	contained
- syn region texStyleMatcher		matchgroup=Delimiter start="\["				end="]"		contains=@texStyleGroup,texError	contained
+ if !exists("g:tex_fast") || g:tex_fast =~ 'S'
+  syn region texStyleMatcher		matchgroup=Delimiter start="{" skip="\\\\\|\\[{}]"	end="}"		contains=@texStyleGroup,texError	contained
+  syn region texStyleMatcher		matchgroup=Delimiter start="\["				end="]"		contains=@texStyleGroup,texError	contained
+ endif
 endif
 
 " Conceal mode support (supports set cole=2) {{{1
@@ -970,8 +1014,10 @@
 
  " Superscripts/Subscripts {{{2
  if s:tex_conceal =~ 's'
-  syn region texSuperscript	matchgroup=Delimiter start='\^{'	skip="\\\\\|\\[{}]" end='}'	contained concealends contains=texSpecialChar,texSuperscripts,texStatement,texSubscript,texSuperscript,texMathMatcher
-  syn region texSubscript	matchgroup=Delimiter start='_{'		skip="\\\\\|\\[{}]" end='}'	contained concealends contains=texSpecialChar,texSubscripts,texStatement,texSubscript,texSuperscript,texMathMatcher
+  if !exists("g:tex_fast") || g:tex_fast =~ 's'
+   syn region texSuperscript	matchgroup=Delimiter start='\^{'	skip="\\\\\|\\[{}]" end='}'	contained concealends contains=texSpecialChar,texSuperscripts,texStatement,texSubscript,texSuperscript,texMathMatcher
+   syn region texSubscript	matchgroup=Delimiter start='_{'		skip="\\\\\|\\[{}]" end='}'	contained concealends contains=texSpecialChar,texSubscripts,texStatement,texSubscript,texSuperscript,texMathMatcher
+  endif
   fun! s:SuperSub(group,leader,pat,cchar)
     exe 'syn match '.a:group." '".a:leader.a:pat."' contained conceal cchar=".a:cchar
     exe 'syn match '.a:group."s '".a:pat."' contained conceal cchar=".a:cchar.' nextgroup='.a:group.'s'
@@ -1180,7 +1226,7 @@
 if did_tex_syntax_inits == 1
  let did_tex_syntax_inits= 2
   " TeX highlighting groups which should share similar highlighting
-  if !exists("g:tex_no_error")
+  if !exists("s:tex_no_error")
    if !exists("tex_no_math")
     HiLink texBadMath		texError
     HiLink texMathDelimBad	texError