Dear List, I've been trying to construct part of a block's content programmatically with Lua. Despite many experiments and much rereading of the cld manual (especially chapter 3 on functions), the following attempt fails for reasons that perplex me. Below is the MNWE (Minimal NonWorking Example). It fails with these lines in the log file: structure > sectioning > subject @ level 3 : 0.0.0 -> Answers tex error > tex error on line 1 in file virtual://block.answer.1: ! Undefined control sequence l.1 \oneargTestparameter That is, when the "answer" block is included via \useblocks, somehow the beginning of the answer, which should be "\onearg{Test parameter}", has its curly braces and spaces elided. What characteristic(s) of the Lua interface am I missing? Thank you if you happen to where I've gone wrong. I've also tried steppers without much luck (and, admittedly, without really understanding their use). =============== testluabeginblock.tex =============== \defineblock[answer] \hideblocks[answer] \def\onearg#1{{\bf #1}} \def\noarg{{\it fixed argument}} \starttext \startluacode context.beginanswer() context("\\onearg{Test parameter}") \stopluacode This is part of the answer. \endanswer \subject{Answers} \useblocks[answer] \stoptext =============== end testluabeginblock.tex =============== -Sanjoy