Hi, If it is this (see image below), what you want. Just use wikitext and the KaTeX plugin. see: https://tiddlywiki.com/plugins/tiddlywiki/katex/
and write $$ !! a'' + <a> $$ IMO it works just fine: have fun! mario -- You received this message because you are subscribed to the Google Groups "TiddlyWiki" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/tiddlywiki/3a3846d5-1ae1-4baf-8bdf-eb62c6f9b150%40googlegroups.com.

