<\body> converters> to converter> Some of the primitives have no analogues in . When converting such primitives from into , they will usually be either ignored or replaced by an approximative translation. A (probably incomplete) list of features with no counterparts is as follows: <\itemize> Left primes. Big separators between big parentheses. Trees. Certain features of tables (background color, cell span, vertical alignment, ). Complex user macros. Vertical spaces ``before'' and ``after''. Indentation flags ``before'' and ``after''. Most types of interactive content: hyperlinks, actions, sessions, tags for the presentation mode, animations and sounds, etc. In addition, several issues are only partially implemented: <\itemize> Non standard fonts. Certain table properties Style parameters. Of course, there are also differences between the typesetting algorithms used by and /, so the to is not intended to be . to converter> As explained in the introduction, the conversion of documents into is more problematic than conversions the other way around. Only a subset of can be converted to in a fully reliable way. This subset comprises virtually all common constructs, including macro definitions and the additional macros uses by the to converter. However, the converter has no knowledge about style parameters. In particular, it cannot be used for the conversion of style files. <\initial> <\collection>