Hi, I uploaded a new version of lmtx and there are some experimental features that users cna play with so that we can think about related interfacing. (I won't mention soem in the lua department that I'm still exploring myself.) When you use a math symbol its class property determines the spacing. One can use \mathopen etc to wrap such a character an dmake it behave different. There is a new mechanism to overload that property in a different way: \startlines $x\mathopen {!}+123+\mathclose {!}x$ $x\tomathopen ! +123+\tomathclose ! x$ $x\mathclose {!}+123+\mathopen {!}x$ $x\tomathclose ! +123+\tomathopen ! x$ $x ! +123+ ! x$ \stoplines It uses a low level primitive, for the open case: \Umathclass 4 with the number being the desired class. A more experimental features concerns native prescripts. Consider the following input \blank \hbox{$ {\tf X}^1_2^^3__4 \quad {\tf X}^1 ^^3 \quad {\tf X} _1 __4 \quad {\tf X} ^^3 \quad {\tf X} __4 \quad {\tf X}^^3 __4 $} \blank or with the control sequence variants: \blank \hbox{ \ruledhbox{${\tf X}\Usuperscript{a} $} \ruledhbox{${\tf X} \Usubscript{b} $} \ruledhbox{${\tf X}\Usuperscript{a}\Usubscript{b} $} \ruledhbox{${\tf X}\Usuperscript{a} \Usuperprescript{c} $} \ruledhbox{${\tf X} \Usubscript{b} \Usubprescript{d}$} \ruledhbox{${\tf X}\Usuperscript{a}\Usubscript{b}\Usuperprescript{c}\Usubprescript{d}$} \ruledhbox{${\tf X} \Usuperprescript{c} $} \ruledhbox{${\tf X} \Usubprescript{d}$} \ruledhbox{${\tf X} \Usuperprescript{c}\Usubprescript{d}$} } \blank A few days ago there was a discussion about tweaking some math parameters, like the radical spacing. I made a macro that deals with it: $\mathopenupparameter\Umathradicalvgap{10.5}\sqrt[3]{x}$ (this one is also in mkiv, be it slightly less efficient because in lmtx we can use \Umathparameter to query the state of a variable) Already present was a variant on \over which normally is used like {{1}\over{2}} i.e. the only time when tex looks back and needs to tweak styles. The alternative is: $\Uover{1}{2}$ etc which looks forward but is otherwise compatible, apart from supporting an optional keyword $\Uover style \scriptscriptstyle{1}{2}$ etc $\Uover style \textstyle{1}{2}$ etc At some point I will adapt some context code to this. Anyway, these are things that low level math users might like to play with. There are few more things but those will probably go unnoticed. Hans ----------------------------------------------------------------- Hans Hagen | PRAGMA ADE Ridderstraat 27 | 8061 GH Hasselt | The Netherlands tel: 038 477 53 69 | www.pragma-ade.nl | www.pragma-pod.nl -----------------------------------------------------------------