Update SCDocSyntax.schelp

Updated according to the old MathJax support version (before 16 July 2013).

HelpSource/Reference/SCDocSyntax.schelp

@@ -251,7 +251,7 @@ Just leave the caption empty if you want a link but no caption.
 
 ::
 
-The following tags (CODE and TELETYPE) can be written in two forms, either inline or block.
+The following tags (CODE, TELETYPE and MATH) can be written in two forms, either inline or block.
 strong::Inline:: form has the end-tag on the same line, and need any enclosed double-colons that should be part of the text to be escaped with backslash (teletype:: \ ::).
 strong::Block:: form has the tag and end-tag on lines by themselves, and can take multi-line text. In block form, only a single end-tag on its own line counts and any end-tags inside the text should not be escaped (except if it's on a single line).
 
@@ -271,6 +271,21 @@ teletype:: CODE\:: ::
 ## keyword:: teletype\::
 teletype:: TELETYPE\:: ::
 || Render monospace text.
+## keyword:: math\::
+teletype:: MATH\:: ::
+|| Render mathematics given in TeX syntax. Example:
+teletype::
+This is inline math::2\pi:: and below is block display math:
+math::
+1\over\sqrt{x^\pi}
+\::
+::
+Renders:
+
+This is inline math::2\pi:: and below is block display math:
+math::
+1\over\sqrt{x^\pi}
+::
 ::
 
 subsection:: Lists and tables
@@ -428,9 +443,11 @@ inlinetag         ::= "LINK::"
                     | "EMPHASIS::"
                     | "CODE::"
                     | "TELETYPE::"
+                    | "MATH::"
                     | "ANCHOR::"
 blocktag          ::= CODEBLOCK
                     | TELETYPEBLOCK
+                    | MATHBLOCK
 listtag           ::= "LIST::"
                     | "TREE::"
                     | "NUMBEREDLIST::"
@@ -460,4 +477,3 @@ nocommawords      ::= nocommawords TEXT
                     | URL
 commalist         ::= { nocommawords COMMA } nocommawords
 ::
-