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LaTeX reserved ASCII characters

Some ASCII characters are interpreted as special command names or arguments causing them not appearing in the output or returning "Failed to parse (syntax error / lexing error)" error outputs. For displaying them as symbols (escaping LaTeX command names or arguments), correct syntax is adding a backslash (\) in front of character.

Title

Symbol	LaTeX Usage	Error Output if mising backslash (without a backslash in front)	Correct syntax (adding backslash in front)
	Start a command name	Failed to parse (lexing error): \	<math>\backslash\,</math>
	Start a command argument.	Failed to parse (syntax error): {	<math>\{\,</math>
	End a command argument.	Failed to parse (syntax error): }	<math>\}\,</math>
	Subscript.	Failed to parse (syntax error): _	<math>\_\,</math>
	Superscript.	Failed to parse (syntax error): ^	<math>\wedge</math>
	Refer to arguments in macro definitions.	Failed to parse (lexing error): #	<math>\#</math>
	Tie words with unbreakable space.		<math>\sim\,</math>
	Separate column entries in tables.	Failed to parse (syntax error): &	<math>\And</math>
	Ends a row in tables.	Failed to parse (syntax error): \\	<math>\backslash\backslash</math>

Subscripts & Superscripts

To get an expression exp to appear as a subscript, you just type _{exp}. To get exp to appear as a superscript, you type ^{exp}. LaTeX handles superscripted superscripts and all of that stuff in the natural way. It even does the right thing when something has both a subscript and a superscript.

Spacing and Forced PNG rendering

LaTeX markup ignores the spaces you type and puts in the spacing that it thinks is best.

Example 3:

Displaying a set of the first 3 greek letters

Spacing	LaTeX command	Output
no space	<math>\alpha \beta \gamma</math>	αβγ
text space without forced PNG	<math>\alpha \mbox{ }\beta \mbox{ }\gamma</math>	α β γ
negative thin space - \!	<math>\alpha\!\beta\!\gamma</math>
thin space - \,	<math>\alpha\,\beta\,\gamma</math>
thick space - \;	<math>\alpha\;\beta\;\gamma</math>
text space - \	<math>\alpha \ \beta \ \gamma</math>
quad space (1em) - \quad	<math>\alpha\quad\beta\quad\gamma</math>
double quad space (2em) - \qquad	<math>\alpha\qquad\beta\qquad\gamma</math>

To force the formula to render as PNG, add \, (thin space) at the end of the formula (where it is not rendered). This will force PNG if the user is in "HTML if simple" mode, but not for "HTML if possible" mode (math rendering settings in preferences). See your preferences tab.

You can also use \,\! (thin space and negative space, which cancel out) anywhere inside the math tags. This does force PNG even in "HTML if possible" mode, unlike \,. See your preferences tab.

Example 5:

For rendering the square root of five, do this (in editing mode):

1. Click on button
2. Text <math>Insert formula here</math> will be added to your edition
3. Substitute "Insert formula here" by TeX code: <math>\sqrt{5}\,\!</math>
4. symbol will be rendered in your text.

Example 6:

• Typing <math>a^{c+2}</math> you may get (depending on your preferences): a^{c + 2}
• But typing <math>a^{c+2}\,\!</math> you will get

Vertical alignment

Value	Output
no value	Science more text here
0%	Science more text here
-25%	Science more text here
-50%	Science more text here
-75%	Science more text here
-100%	SCIENCE x human progress

Table 1:   Escapable "Special" Characters

Code	Output	Code	Output	Code	Output	Code	Output
\$		\%		\_	_ *	\}	}
\&	Failed to parse (lexing error): \&	\#		\{	{

* The underscore package redefines \_" to produce an underscore in text mode (i.e., it makes it unnecessary to escape the underscore character).

Table 2: Predefined   Text-mode Commands

Table 3:   Commands Defined to Work in Both Math and Text Mode

Code	Output	Code	Output	Code	Output	Code	Output
\$		\_	_	\ddag	Failed to parse (unknown function\ddag): \ddag	\{	{
\P		\copyright	Failed to parse (unknown function\copyright): \copyright	\dots		\}	}
\S		\dag	Failed to parse (unknown function\dag): \dag	\pounds	Failed to parse (unknown function\pounds): \pounds

Where two symbols are present, the left one is the "\faked" symbol that   provides by default, and the right one is the \true" symbol that textcomp makes available.

Table 4: Commands Defined to Work in Both Math and Text Mode

Code	Output	Code	Output	Code	Output
\checkmark		\circledR	Failed to parse (unknown function\circledR): \circledR	\maltese	Failed to parse (unknown function\maltese): \maltese

Table 5: Non-ASCII Letters (Excluding Accented Letters)

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Work in progress, expect frequent changes. Help and feedback is welcome. See discussion page.