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"http://www.w3.org/TR/REC-html40/loose.dtd">
Definitions, Numbering
HEVEA understands command definitions given in LATEX style. Such definitions are made using \newcommand , \renewcommand and \providecommand .
These three constructs accept the same arguments and have the same
meaning as in LATEX, in particular it is possible to define an user
command with one optional argument.
However, HEVEA is more tolerant: if command
name already exists, then a subsequent \newcommand{ name} ...is ignored. If macro name does not exists, then
\renewcommand{ name} ...performs a definition of name. In both cases, LATEX would crash, HEVEA just issues
warnings.The behavior of \newcommand allows to shadow document
definition, provided the new definitions are processed before the
document definitions.
This is easily done by grouping the shadowing definition in a
specific style file given as an argument to HEVEA (see section 5.1).
Conversely, changes of base macros (i.e., the ones that HEVEA
defines before loading any user-specified file) must be performed
using \renewcommand .Scoping rules apply to macros, as they do in LATEX. Environments and groups define a scope and command definition are local to the scope they occur. It is worth noticing that HEVEA also partly implements TeX definitions (using \def ) and bindings (using \let ), see
section B.16.2 for details.
\newenvironment and \renewenvironment .
The support is complete and should conform
to [LATEX, Sections C.8.2].Environments define a scope both for commands and environment definitions.
\newtheorem and \renewtheorem .Note that, by contrast with plain environments definitions, theorem-like environment definitions are global definitions.
\newcounter{ cmd} creates a macro
\the cmd that outputs the counter value.
Then the \the cmd command can be redefined.
For instance, section numbering can be turned into alphabetic style by:
\renewcommand{\thesection}{\alph{section}}Note that TeX style for counters is not supported at all and that using this style will clobber the output. However, HEVEA implements the calc package that makes using TeX style for counters useless in most situations (see section B.17.3).
The ifthen package is partially supported. The one unsupported construct is the \lengthtest test expression, which is
undefined.As a consequence, HEVEA accepts the following example from the LATEX manual: \newcounter{ca}\newcounter{cb}% \newcommand{\printgcd}[2]{% \setcounter{ca}{#1}\setcounter{cb}{#2}% Gcd(#1,#2) = \whiledo{\not\(\value{ca}= \value{cb}\)}% {\ifthenelse{\value{ca}>\value{cb}}% {\addtocounter{ca}{-\value{cb}}}% {\addtocounter{cb}{-\value{ca}}}% gcd(\arabic{ca}, \arabic{cb}) = }% \arabic{ca}.}% For example: \printgcd{54}{30}For example: Gcd(54,30) = gcd(24, 30) = gcd(24, 6) = gcd(18, 6) = gcd(12, 6) = gcd(6, 6) = 6. Additionally, a few boolean registers are defined by HEVEA. Some of them are of interest to users.
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