diff --git a/runtime/doc/message.txt b/runtime/doc/message.txt
index 97a1882159..e8c76adad4 100644
--- a/runtime/doc/message.txt
+++ b/runtime/doc/message.txt
@@ -780,6 +780,7 @@ To reduce the number of hit-enter prompts:
 - Set 'cmdheight' to 2 or higher.
 - Add flags to 'shortmess'.
 - Reset 'showcmd' and/or 'ruler'.
+- Make sure `:echo` text is within |v:echospace| screen cells.
 
 If your script causes the hit-enter prompt and you don't know why, you may
 find the |v:scrollstart| variable useful.
diff --git a/runtime/filetype.vim b/runtime/filetype.vim
index cbb31de7dd..6abf9da55f 100644
--- a/runtime/filetype.vim
+++ b/runtime/filetype.vim
@@ -1,7 +1,7 @@
 " Vim support file to detect file types
 "
 " Maintainer:	Bram Moolenaar <Bram@vim.org>
-" Last Change:	2019 Jul 27
+" Last Change:	2019 Aug 26
 
 " Listen very carefully, I will say this only once
 if exists("did_load_filetypes")
diff --git a/runtime/pack/dist/opt/termdebug/plugin/termdebug.vim b/runtime/pack/dist/opt/termdebug/plugin/termdebug.vim
index 6288782019..a97461ad69 100644
--- a/runtime/pack/dist/opt/termdebug/plugin/termdebug.vim
+++ b/runtime/pack/dist/opt/termdebug/plugin/termdebug.vim
@@ -239,6 +239,10 @@ func s:StartDebug_term(dict)
           " Success!
           break
         endif
+        if response =~ 'Reading symbols from' && response !~ 'new-ui'
+          " Reading symbols might take a while
+	  let try_count -= 1
+        endif
       endif
     endfor
     if response =~ 'New UI allocated'
diff --git a/runtime/syntax/css.vim b/runtime/syntax/css.vim
index ecdbc1795c..73bbd8d03f 100644
--- a/runtime/syntax/css.vim
+++ b/runtime/syntax/css.vim
@@ -6,8 +6,7 @@
 "               Nikolai Weibull (Add CSS2 support)
 " URL:          https://github.com/JulesWang/css.vim
 " Maintainer:   Jules Wang      <w.jq0722@gmail.com>
-" Last Change:  2018 Feb. 27
-"               cssClassName updated by Ryuichi Hayashida Jan 2016
+" Last Change:  2019 Jul. 29
 
 " quit when a syntax file was already loaded
 if !exists("main_syntax")
@@ -69,7 +68,7 @@ endtry
 " digits
 syn match cssValueInteger contained "[-+]\=\d\+" contains=cssUnitDecorators
 syn match cssValueNumber contained "[-+]\=\d\+\(\.\d*\)\=" contains=cssUnitDecorators
-syn match cssValueLength contained "[-+]\=\d\+\(\.\d*\)\=\(mm\|cm\|in\|pt\|pc\|em\|ex\|px\|rem\|dpi\|dppx\|dpcm\)\>" contains=cssUnitDecorators
+syn match cssValueLength contained "[-+]\=\d\+\(\.\d*\)\=\(mm\|cm\|in\|pt\|pc\|em\|ex\|px\|rem\|dpi\|dppx\|dpcm\|fr\|vw\|vh\|vmin\|vmax\)\>" contains=cssUnitDecorators
 syn match cssValueLength contained "[-+]\=\d\+\(\.\d*\)\=%" contains=cssUnitDecorators
 syn match cssValueAngle contained "[-+]\=\d\+\(\.\d*\)\=\(deg\|grad\|rad\)\>" contains=cssUnitDecorators
 syn match cssValueTime contained "+\=\d\+\(\.\d*\)\=\(ms\|s\)\>" contains=cssUnitDecorators
@@ -114,6 +113,7 @@ syn keyword cssColor contained ActiveBorder ActiveCaption AppWorkspace ButtonFac
 syn case ignore
 
 syn match cssImportant contained "!\s*important\>"
+syn match cssCustomProp contained "--[a-zA-Z0-9-_]*"
 
 syn match cssColor contained "\<transparent\>"
 syn match cssColor contained "\<currentColor\>"
@@ -123,6 +123,7 @@ syn match cssColor contained "#\x\{6\}\>" contains=cssUnitDecorators
 syn match cssColor contained "#\x\{8\}\>" contains=cssUnitDecorators
 
 syn region cssURL contained matchgroup=cssFunctionName start="\<\(uri\|url\|local\|format\)\s*(" end=")" contains=cssStringQ,cssStringQQ oneline
+syn region cssFunction contained matchgroup=cssFunctionName start="\<\(var\|calc\)\s*(" end=")" contains=cssCustomProp,cssValue.*,cssFunction,cssColor,cssStringQ,cssStringQQ oneline
 syn region cssFunction contained matchgroup=cssFunctionName start="\<\(rgb\|clip\|attr\|counter\|rect\|cubic-bezier\|steps\)\s*(" end=")" oneline  contains=cssValueInteger,cssValueNumber,cssValueLength,cssFunctionComma
 syn region cssFunction contained matchgroup=cssFunctionName start="\<\(rgba\|hsl\|hsla\|color-stop\|from\|to\)\s*(" end=")" oneline  contains=cssColor,cssValueInteger,cssValueNumber,cssValueLength,cssFunctionComma,cssFunction
 syn region cssFunction contained matchgroup=cssFunctionName start="\<\(linear-\|radial-\)\=\gradient\s*(" end=")" oneline  contains=cssColor,cssValueInteger,cssValueNumber,cssValueLength,cssFunction,cssGradientAttr,cssFunctionComma
@@ -193,6 +194,9 @@ syn match cssBoxProp contained "\<rotation\(-point\)\=\>"
 syn keyword cssBoxAttr contained visible hidden scroll auto
 syn match cssBoxAttr contained "\<no-\(display\|content\)\>"
 
+syn keyword cssCascadeProp contained all
+syn keyword cssCascadeAttr contained initial unset revert
+
 syn keyword cssColorProp contained opacity
 syn match cssColorProp contained "\<color-profile\>"
 syn match cssColorProp contained "\<rendering-intent\>"
@@ -273,10 +277,10 @@ syn match cssGeneratedContentAttr contained "\<\(no-\)\=\(open\|close\)-quote\>"
 
 " https://www.w3.org/TR/css-grid-1/
 syn match cssGridProp contained "\<grid\>"
-syn match cssGridProp contained "\<grid\(-\(template\|auto\)\)\=\(-\(columns\|rows\|areas\)\)\>"
+syn match cssGridProp contained "\<grid-template\(-\(columns\|rows\|areas\)\)\=\>"
 syn match cssGridProp contained "\<grid-\(column\|row\)\(-\(start\|end\|gap\)\)\=\>"
 syn match cssGridProp contained "\<grid-\(area\|gap\)\>"
-syn match cssGridProp contained "\<grid-auto-flow\>"
+syn match cssGridProp contained "\<grid-auto-\(flow\|rows\|columns\)\>"
 
 syn match cssHyerlinkProp contained "\<target\(-\(name\|new\|position\)\)\=\>"
 
@@ -295,6 +299,7 @@ syn match cssPositioningAttr contained "\<table\(-\(row-group\|\(header\|footer\
 syn keyword cssPositioningAttr contained left right both
 syn match cssPositioningAttr contained "\<list-item\>"
 syn match cssPositioningAttr contained "\<inline\(-\(block\|box\|table\|grid\|flex\)\)\=\>"
+syn match cssPositioningAttr contained "\<flow\(-root\)\=\>"
 syn keyword cssPositioningAttr contained static relative absolute fixed subgrid
 
 syn keyword cssPrintAttr contained landscape portrait crop cross always
@@ -303,12 +308,13 @@ syn match cssTableProp contained "\<\(caption-side\|table-layout\|border-collaps
 syn keyword cssTableAttr contained fixed collapse separate show hide once always
 
 
-syn keyword cssTextProp contained color direction
+syn keyword cssTextProp contained color direction hyphens
 syn match cssTextProp "\<\(\(word\|letter\)-spacing\|text\(-\(decoration\|transform\|align\|index\|shadow\)\)\=\|vertical-align\|unicode-bidi\|line-height\)\>"
 syn match cssTextProp contained "\<text-\(justify\|outline\|warp\|align-last\|size-adjust\|rendering\|stroke\|indent\)\>"
-syn match cssTextProp contained "\<word-\(break\|\wrap\)\>"
+syn match cssTextProp contained "\<\(word\|line\)-break\|\(overflow\|word\)-wrap\>"
 syn match cssTextProp contained "\<white-space\>"
 syn match cssTextProp contained "\<hanging-punctuation\>"
+syn match cssTextProp contained "\<tab-size\>"
 syn match cssTextProp contained "\<punctuation-trim\>"
 syn match cssTextAttr contained "\<line-through\>"
 syn match cssTextAttr contained "\<\(text-\)\=\(top\|bottom\)\>"
@@ -316,7 +322,7 @@ syn keyword cssTextAttr contained ltr rtl embed nowrap
 syn keyword cssTextAttr contained underline overline blink sub super middle
 syn keyword cssTextAttr contained capitalize uppercase lowercase
 syn keyword cssTextAttr contained justify baseline sub super
-syn keyword cssTextAttr contained optimizeLegibility optimizeSpeed
+syn keyword cssTextAttr contained optimizeLegibility optimizeSpeed geometricPrecision
 syn match cssTextAttr contained "\<pre\(-\(line\|wrap\)\)\=\>"
 syn match cssTextAttr contained "\<\(allow\|force\)-end\>"
 syn keyword cssTextAttr contained start end adjacent
@@ -325,7 +331,7 @@ syn keyword cssTextAttr contained distribute kashida first last
 syn keyword cssTextAttr contained clip ellipsis unrestricted suppress
 syn match cssTextAttr contained "\<break-all\>"
 syn match cssTextAttr contained "\<break-word\>"
-syn keyword cssTextAttr contained hyphenate
+syn keyword cssTextAttr contained manual
 syn match cssTextAttr contained "\<bidi-override\>"
 
 syn match cssTransformProp contained "\<transform\(-\(origin\|style\)\)\=\>"
@@ -408,13 +414,13 @@ syn keyword cssAuralAttr contained male female child code digits continuous
 " mobile text
 syn match cssMobileTextProp contained "\<text-size-adjust\>"
 
-syn keyword cssMediaProp contained width height orientation scan grid
+syn keyword cssMediaProp contained width height orientation scan
 syn match cssMediaProp contained /\(\(max\|min\)-\)\=\(\(device\)-\)\=aspect-ratio/
 syn match cssMediaProp contained /\(\(max\|min\)-\)\=device-pixel-ratio/
 syn match cssMediaProp contained /\(\(max\|min\)-\)\=device-\(height\|width\)/
 syn match cssMediaProp contained /\(\(max\|min\)-\)\=\(height\|width\|resolution\|monochrome\|color\(-index\)\=\)/
 syn keyword cssMediaAttr contained portrait landscape progressive interlace
-syn match cssKeyFrameProp /\d*%\|from\|to/  contained nextgroup=cssDefinition
+syn match cssKeyFrameProp contained /\(\d\+\(\.\d\+\)\?%\|\(\<from\|to\>\)\)/ nextgroup=cssDefinition
 syn match cssPageMarginProp /@\(\(top\|left\|right\|bottom\)-\(left\|center\|right\|middle\|bottom\)\)\(-corner\)\=/ contained nextgroup=cssDefinition
 syn keyword cssPageProp contained content size
 syn keyword cssPageProp contained orphans widows
@@ -426,7 +432,7 @@ syn match cssFontDescriptorAttr contained "U+\x\+-\x\+"
 
 syn match cssBraces contained "[{}]"
 syn match cssError contained "{@<>"
-syn region cssDefinition transparent matchgroup=cssBraces start='{' end='}' contains=cssTagName,cssAttributeSelector,cssClassName,cssIdentifier,cssAtRule,cssAttrRegion,css.*Prop,cssComment,cssValue.*,cssColor,cssURL,cssImportant,cssError,cssStringQ,cssStringQQ,cssFunction,cssUnicodeEscape,cssVendor,cssDefinition,cssHacks,cssNoise fold
+syn region cssDefinition transparent matchgroup=cssBraces start='{' end='}' contains=cssTagName,cssAttributeSelector,cssClassName,cssIdentifier,cssAtRule,cssAttrRegion,css.*Prop,cssComment,cssValue.*,cssColor,cssURL,cssImportant,cssCustomProp,cssError,cssStringQ,cssStringQQ,cssFunction,cssUnicodeEscape,cssVendor,cssDefinition,cssHacks,cssNoise fold
 syn match cssBraceError "}"
 syn match cssAttrComma ","
 
@@ -437,7 +443,7 @@ syn keyword cssPseudoClassId contained link visited active hover before after le
 syn keyword cssPseudoClassId contained root empty target enable disabled checked invalid
 syn match cssPseudoClassId contained "\<first-\(line\|letter\)\>"
 syn match cssPseudoClassId contained "\<\(first\|last\|only\)-\(of-type\|child\)\>"
-syn region cssPseudoClassFn contained matchgroup=cssFunctionName start="\<\(not\|lang\|\(nth\|nth-last\)-\(of-type\|child\)\)(" end=")"
+syn region cssPseudoClassFn contained matchgroup=cssFunctionName start="\<\(not\|lang\|\(nth\|nth-last\)-\(of-type\|child\)\)(" end=")" contains=cssStringQ,cssStringQQ
 " ------------------------------------
 " Vendor specific properties
 syn match cssPseudoClassId contained  "\<selection\>"
@@ -470,19 +476,20 @@ syn match cssHacks contained /\(_\|*\)/
 
 " Attr Enhance
 " Some keywords are both Prop and Attr, so we have to handle them
-syn region cssAttrRegion start=/:/ end=/\ze\(;\|)\|}\)/ contained contains=css.*Attr,cssColor,cssImportant,cssValue.*,cssFunction,cssString.*,cssURL,cssComment,cssUnicodeEscape,cssVendor,cssError,cssAttrComma,cssNoise
+" cssPseudoClassId is hidden by cssAttrRegion, so we add it here. see #69
+syn region cssAttrRegion start=/:/ end=/\ze\(;\|)\|}\|{\)/ contained contains=cssPseudoClassId,css.*Attr,cssColor,cssImportant,cssValue.*,cssFunction,cssString.*,cssURL,cssComment,cssUnicodeEscape,cssVendor,cssError,cssAttrComma,cssNoise
 
 " Hack for transition
 " 'transition' has Props after ':'.
 syn region cssAttrRegion start=/transition\s*:/ end=/\ze\(;\|)\|}\)/ contained contains=css.*Prop,css.*Attr,cssColor,cssImportant,cssValue.*,cssFunction,cssString.*,cssURL,cssComment,cssUnicodeEscape,cssVendor,cssError,cssAttrComma,cssNoise
 
-syn match cssAtKeyword /@\(font-face\|media\|keyframes\|import\|charset\|namespace\|page\|supports\)/ contained
+syn match cssAtKeyword /@\(font-face\|media\|keyframes\|import\|charset\|namespace\|page\|supports\)/
 
 syn keyword cssAtRuleLogical only not and contained
 
 " @media
 " Reference: http://www.w3.org/TR/css3-mediaqueries/
-syn region cssAtRule start=/@media\>/ end=/\ze{/ skipwhite skipnl matchgroup=cssAtKeyword contains=cssMediaProp,cssValueLength,cssAtRuleLogical,cssValueInteger,cssMediaAttr,cssVendor,cssMediaType,cssComment nextgroup=cssDefinition
+syn region cssAtRule start=/@media\>/ end=/\ze{/ skipwhite skipnl matchgroup=cssAtKeyword contains=cssMediaProp,cssValueLength,cssAtRuleLogical,cssValueInteger,cssMediaAttr,cssVendor,cssMediaType,cssComment,cssCustomProp,cssFunctionName nextgroup=cssDefinition
 syn keyword cssMediaType contained screen print aural braille embossed handheld projection tty tv speech all contained
 
 " @page
@@ -497,9 +504,6 @@ syn region cssAtRule start=/@import\>/    end=/\ze;/ contains=cssStringQ,cssStri
 syn region cssAtRule start=/@charset\>/   end=/\ze;/ contains=cssStringQ,cssStringQQ,cssUnicodeEscape,cssComment,cssAtKeyword
 syn region cssAtRule start=/@namespace\>/ end=/\ze;/ contains=cssStringQ,cssStringQQ,cssUnicodeEscape,cssComment,cssAtKeyword
 
-" @font-face
-" http://www.w3.org/TR/css3-fonts/#at-font-face-rule
-syn match cssAtRule "@font-face\>" nextgroup=cssFontDescriptorBlock
 " @supports
 " https://www.w3.org/TR/css3-conditional/#at-supports
 syn region cssAtRule start=/@supports\>/ end=/\ze{/ skipwhite skipnl contains=cssAtRuleLogical,cssAttrRegion,css.*Prop,cssValue.*,cssVendor,cssAtKeyword,cssComment nextgroup=cssDefinition
@@ -525,6 +529,7 @@ hi def link cssAnimationProp cssProp
 hi def link cssBackgroundProp cssProp
 hi def link cssBorderProp cssProp
 hi def link cssBoxProp cssProp
+hi def link cssCascadeProp cssProp
 hi def link cssColorProp cssProp
 hi def link cssContentForPagedMediaProp cssProp
 hi def link cssDimensionProp cssProp
@@ -585,6 +590,7 @@ hi def link cssUIAttr cssAttr
 hi def link cssIEUIAttr cssAttr
 hi def link cssAuralAttr cssAttr
 hi def link cssRenderAttr cssAttr
+hi def link cssCascadeAttr cssAttr
 hi def link cssCommonAttr cssAttr
 
 hi def link cssPseudoClassId PreProc
@@ -604,6 +610,7 @@ hi def link cssIdentifier Function
 hi def link cssAtRule Include
 hi def link cssAtKeyword PreProc
 hi def link cssImportant Special
+hi def link cssCustomProp Special
 hi def link cssBraces Function
 hi def link cssBraceError Error
 hi def link cssError Error
diff --git a/runtime/syntax/murphi.vim b/runtime/syntax/murphi.vim
index b2faa8c119..347e17f5ac 100644
--- a/runtime/syntax/murphi.vim
+++ b/runtime/syntax/murphi.vim
@@ -1,7 +1,7 @@
 " Vim syntax file
 " Language: Murphi model checking language
 " Maintainer: Matthew Fernandez <matthew.fernandez@gmail.com>
-" Last Change: 2017 Aug 27
+" Last Change: 2019 Aug 27
 " Version: 2
 " Remark: Originally authored by Diego Ongaro <ongaro@cs.stanford.edu> 
 
@@ -61,7 +61,6 @@ syn keyword murphiFunction      multisetcount
 syn keyword murphiFunction      multisetremove
 syn keyword murphiFunction      multisetremovepred
 syn keyword murphiKeyword       procedure
-syn keyword murphiKeyword       process
 syn keyword murphiKeyword       program
 syn keyword murphiKeyword       put
 syn keyword murphiStructure     record
@@ -89,7 +88,7 @@ syn match murphiNumber "\<\d\+\>"
 
 " Operators and special characters.
 syn match murphiOperator "[\+\-\*\/%&|=!<>:\?]\|\."
-syn match murphiDelimiter "\(:[^=]\|[;,]\)"
+syn match murphiDelimiter "\(:=\@!\|[;,]\)"
 syn match murphiSpecial "[()\[\]]"
 
 " Double equal sign is a common error: use one equal sign for equality testing.
diff --git a/runtime/syntax/prolog.vim b/runtime/syntax/prolog.vim
index 3b09bb3548..58b279b029 100644
--- a/runtime/syntax/prolog.vim
+++ b/runtime/syntax/prolog.vim
@@ -1,14 +1,14 @@
 " Vim syntax file
 " Language:    PROLOG
-" Maintainer:  Thomas Koehler <jean-luc@picard.franken.de>
-"              Please be aware: I'm often slow to answer email due to a high
-"              non-computer related workload (sometimes 4-8 weeks)
-" Last Change: 2016 September 6
-" URL:         http://gott-gehabt.de/800_wer_wir_sind/thomas/Homepage/Computer/vim/syntax/prolog.vim
+" Maintainer:  Anton Kochkov <anton.kochkov@gmail.com>
+" Last Change: 2019 Aug 29
 
 " There are two sets of highlighting in here:
 " If the "prolog_highlighting_clean" variable exists, it is rather sparse.
 " Otherwise you get more highlighting.
+"
+" You can also set the "prolog_highlighting_no_keyword" variable. If set,
+" keywords will not be highlighted.
 
 " quit when a syntax file was already loaded
 if exists("b:current_syntax")
@@ -24,7 +24,9 @@ syn case match
 syn region   prologCComment start=+/\*+ end=+\*/+
 syn match    prologComment  +%.*+
 
-syn keyword  prologKeyword  module meta_predicate multifile dynamic
+if !exists("prolog_highlighting_no_keyword")
+  syn keyword  prologKeyword  module meta_predicate multifile dynamic
+endif
 syn match    prologCharCode +0'\\\=.+
 syn region   prologString   start=+"+ skip=+\\\\\|\\"+ end=+"+
 syn region   prologAtom     start=+'+ skip=+\\\\\|\\'+ end=+'+
@@ -35,35 +37,38 @@ if !exists("prolog_highlighting_clean")
   " some keywords
   " some common predicates are also highlighted as keywords
   " is there a better solution?
-  syn keyword prologKeyword   abolish current_output  peek_code
-  syn keyword prologKeyword   append  current_predicate       put_byte
-  syn keyword prologKeyword   arg     current_prolog_flag     put_char
-  syn keyword prologKeyword   asserta fail    put_code
-  syn keyword prologKeyword   assertz findall read
-  syn keyword prologKeyword   at_end_of_stream        float   read_term
-  syn keyword prologKeyword   atom    flush_output    repeat
-  syn keyword prologKeyword   atom_chars      functor retract
-  syn keyword prologKeyword   atom_codes      get_byte        set_input
-  syn keyword prologKeyword   atom_concat     get_char        set_output
-  syn keyword prologKeyword   atom_length     get_code        set_prolog_flag
-  syn keyword prologKeyword   atomic  halt    set_stream_position
-  syn keyword prologKeyword   bagof   integer setof
-  syn keyword prologKeyword   call    is      stream_property
-  syn keyword prologKeyword   catch   nl      sub_atom
-  syn keyword prologKeyword   char_code       nonvar  throw
-  syn keyword prologKeyword   char_conversion number  true
-  syn keyword prologKeyword   clause  number_chars    unify_with_occurs_check
-  syn keyword prologKeyword   close   number_codes    var
-  syn keyword prologKeyword   compound        once    write
-  syn keyword prologKeyword   copy_term       op      write_canonical
-  syn keyword prologKeyword   current_char_conversion open    write_term
-  syn keyword prologKeyword   current_input   peek_byte       writeq
-  syn keyword prologKeyword   current_op      peek_char
+  if !exists("prolog_highlighting_no_keyword")
+    syn keyword prologKeyword   abolish current_output  peek_code
+    syn keyword prologKeyword   append  current_predicate       put_byte
+    syn keyword prologKeyword   arg     current_prolog_flag     put_char
+    syn keyword prologKeyword   asserta fail    put_code
+    syn keyword prologKeyword   assertz findall read
+    syn keyword prologKeyword   at_end_of_stream        float   read_term
+    syn keyword prologKeyword   atom    flush_output    repeat
+    syn keyword prologKeyword   atom_chars      functor retract
+    syn keyword prologKeyword   atom_codes      get_byte        set_input
+    syn keyword prologKeyword   atom_concat     get_char        set_output
+    syn keyword prologKeyword   atom_length     get_code        set_prolog_flag
+    syn keyword prologKeyword   atomic  halt    set_stream_position
+    syn keyword prologKeyword   bagof   integer setof
+    syn keyword prologKeyword   call    is      stream_property
+    syn keyword prologKeyword   catch   nl      sub_atom
+    syn keyword prologKeyword   char_code       nonvar  throw
+    syn keyword prologKeyword   char_conversion number  true
+    syn keyword prologKeyword   clause  number_chars    unify_with_occurs_check
+    syn keyword prologKeyword   close   number_codes    var
+    syn keyword prologKeyword   compound        once    write
+    syn keyword prologKeyword   copy_term       op      write_canonical
+    syn keyword prologKeyword   current_char_conversion open    write_term
+    syn keyword prologKeyword   current_input   peek_byte       writeq
+    syn keyword prologKeyword   current_op      peek_char
+  endif
 
-  syn match   prologOperator "=\\=\|=:=\|\\==\|=<\|==\|>=\|\\=\|\\+\|<\|>\|="
+  syn match   prologOperator "=\\=\|=:=\|\\==\|=<\|==\|>=\|\\=\|\\+\|=\.\.\|<\|>\|="
   syn match   prologAsIs     "===\|\\===\|<=\|=>"
 
-  syn match   prologNumber            "\<[0123456789]*\>'\@!"
+  syn match   prologNumber            "\<\d*\>'\@!"
+  syn match   prologNumber            "\<0[xX]\x*\>'\@!"
   syn match   prologCommentError      "\*/"
   syn match   prologSpecialCharacter  ";"
   syn match   prologSpecialCharacter  "!"