<\body> <\explain> <|explain> This primitive can be used to typeset only if the is satisfied. If the optional is specified, then it is typeset if and only if the fails. <\remark> It should be noticed that the use of conditional markup can be a bit tricky due to the fact that the accessability of arguments cannot necessarily be checked beforehand. For instance, in the macro definition <\tm-fragment> |>>> the macro argument is accessible if and only if > evaluates to true. This condition cannot necessarily be checked . For certain editing operations, like searches or spell checking, the incorrect determination of the accessability may lead to the positioning of the cursor at unaccessible places, or to the ignorance of certain markup. In the future, we plan to improve this aspect of the editor, but it is better to avoid conditional markup whenever another solution can be found. <\remark> The conditional constructs are only fully implemented for inline markup. In the case when you need conditional markup for block structures you currently have to write macros for the if-case and the else-case and use the tag. For instance: <\tm-fragment> >>>> >>>> ||>|>>>> <\explain> >|cond-n|body-n> >|cond-n|body-n|else-body> <|explain> These commands are respectively equivalent to <\tm-fragment> ||>>|>>> ||>>||>>> <\explain> <|explain> This construct maybe used in order to repeatly execute a given while a given is satisfied. For instance, when declaring <\tm-fragment> ||>|, |1>>>>>>>> the code > produces <\tm-fragment> ||>|, |1>>>>>|>