I just run in a tex capacity problem with \prop_map_inline when a property list is not declared and the c-type-Argument is used to fill the list: \documentclass{article} \usepackage{expl3} \begin{document} \ExplSyntaxOn %\prop_new:c{test_prop} %solve the recursion %\prop_gput:Nno\test_prop{datum}{blub} %give error \prop_gput:cno {test_prop}{datum}{bkabka} \prop_show:c{test_prop} \prop_map_inline:cn {test_prop} {#1,#2} \ExplSyntaxOff \end{document} The property list \test_prop contains the pairs (without outer braces): > {datum} => {bkabka}. <recently read> } l.28 \prop_show:N\test_prop ? ! TeX capacity exceeded, sorry [input stack size=5000]. \test_prop ->\test_prop \__prop_pair:wn datum\s__prop {bkabka} Is this a bug? Or simply something one must remember when using c-type arguments? -- Ulrike Fischer http://www.troubleshooting-tex.de/