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- Math Mode Environment
- Common Structures
- Mathematical symbols
- Putting one thing above the other
- Spacing
- Changing Style
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$...$,
\(...\) and
\begin{math}...\end{math}) are supported.
The three ways to use display math mode ($$...$$,
\[...\] and
\begin{displaymath}... \end{displaymath}) are also
supported.
Furthermore, \ensuremath behaves as expected.The
equation, eqnarray, eqnarray* environments
are supported.
Equation labeling and numbering is performed in the first two
environments, using the equation counter.
Additionally, numbering can be suppressed in one row of an
eqnarray, using the \nonumber command.Math mode is not as powerful in HEVEA as in LATEX. The limitations of math mode can often be surpassed by using math display mode. As a matter of fact, math mode is for in-text formulas. From the HTML point of view, this means that math mode does not close the current flow of text and that formulas in math mode must be rendered using text-level elements only. By contrast, displayed formulas can be rendered using block-level elements. This means that HEVEA have much more possibilities in display context than inside normal flow of text. In particular, stacking text elements one above the over is possible only in display context. For instance compare how HEVEA renders
$\frac{1}{\sum_{i=1}^{\infty}$
as: 1/åi=1¥ ii, and
$$\frac{1}{\sum_{i=1}^{\infty}$$ as:
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HEVEA admits, subscript (
_), superscripts (^) and
fractions (\frac{numer}{denom}).
The best effect is obtained in display mode, where HTML
TABLE element is extensively used.
By contrast, when not in display mode, HEVEA uses only
SUB and SUP text-level elements to render superscrits
and subscript, and the result may not be very satisfying.However, simple subscripts and superscripts, such as
x_i or x^2,
are always rendered using the SUB
and SUP text-level elements and their appearance should be correct
even in in-text formulas.When occurring outside math mode, characters
_ and ^ act as
ordinary characters and get echoed to the output. However, a warning
is issued.The nth root command
\sqrt is not supported.
The ``root'' symbol is not necessary, thanks
to fractional exponents. For instance, the \sqrt command can be
defined as follows:
\newcommand{\sqrt}[2][2]{\left(#2\right)^{1/#1}}
Then, the source
fragment: $$\sqrt[3]{\frac{1}{n!}} + \sqrt{\pi}$$ gets rendered
as follows:
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æ ç ç è |
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ö ÷ ÷ ø |
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+ | ( | p | ) |
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An attempt is made to render all ellipsis constructs (
\ldots,
\cdots, \vdots and \ddots). The effect may be
strange for the latter two.
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\leadsto symbol, but it
can be defined as a red arrow by:
\newcommand{\leadsto}{{\red\rightarrow}}
Then, $$A \leadsto B$$ is rendered as follows:
A ® B
When given the
-nosymb option, HEVEA silently replaces
symbols that cannot be rendered by iso-latin1 only by text equivalents.
These equivalents are English words by default, or French words when the
-francais option is set.Log-like functions and variable sized-symbols are recognized and their subscripts and superscripts are put where they should in display mode. Subscript and superscript placement can be changed using the
\limits and \nolimits commands.
Big delimiters are also handled.
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\stackrel, \underline and \overline
are recognized.
They produce sensible output in display mode.
In text mode, these macros call the \textstackrel,
\textunderline and \textoverline macros.
These macros perform the following default actions, which can be
changed by redefining them:
- \textstackrel
- Performs ordinary superscripting.
- \textunderline
- Underlines its argument, using the
Utext-level element. - \textoverline
- Sends a warning message to the console and echoes its argument in the output.
\hat, \tilde, etc.) are not
handled by default.
However, the distribution includes a mathaccents.hva file
that provides definitions for almost all math accents commands,
except \check and \breve.
Rendering is far from perfect and changes from display to text mode.
More precisely, the accent is put (too far) above the symbol in display mode,
and as an ordinary superscript in text mode.
For instance, given the formula
\tilde{v} \cdot \vec{U}, we get
``v~ · U®'' in text mode and
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If such a rendering is considered too ugly, one should not load the mathaccents.hva file and write alternative definitions. For instance, the following custom definitions issue color changes:
\newcommand{\tilde}[1]{{\blue#1}}
\newcommand{\vec}[1]{{\red#1}}
With such definitions the previous example now appears as:
we get
``v · U'' in text mode and
v · U
in display mode.
Of course, such a trick probably requires looking closely at HTML
output to check whether the document is still understandable or not.
It may be better to stay with a poorly formatted document that remains
closer to universally understood notations for mathematics.
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\alpha) are echoed
except for invisible commands (such as \tt).
This allows users to control space in their formulas, output being
near to what can be expected.Explicit spacing commands (
\,, \!, \: and
\;) are recognized, the first two commands do nothing, while
the others two output one space.
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Letters are italicized inside math mode and this cannot be changed. The appearance of other symbols can be changed using LATEX 2e style changing commands (
\mathbf, etc.).
The commands \boldmath and \unboldmath are not
recognized. Whether symbols belonging to the symbol font are affected
by style changes or not is browser dependent.The
\cal declaration and the \mathcal command (that
yield calligraphic letters in LATEX) exist. They yield red letters by
default.Observe that this does not corresponds directly to how LATEX manage style in math mode and that, in fact, style cannot really change in math mode.
Math style changing declarations
\displaystyle and
\textstyle do nothing when HEVEA is already in the requested
mode,
otherwise they issue a warning.
This is so because HEVEA implements displayed maths as tables,
which require to be both opened and closed and introduce line breaks
in the output.
As a consequence, warnings on \displaystyle are to be taken seriously.The commands
\scriptstyle and \scriptscriptstyle
perform type size changes.