Hi, I was trying some math symbols and stumbled over the following commands, that do not work in my context documents (the comments say what's not working exactly). The pasted document works at http://live.contextgarden.net/ . I'm using the latest context-minimals as provided on the website. Is this a MkIV issue? In addition: \ncong is not aligned with = and \cong Thanks in advance! Stefan \starttext \startformula % the following give "Undefined control sequence": \gneq % \lneq works \lhd \rhd \unlhd \unrhd \Diamond % the following produce no symbol: \mapsto \hookleftarrow \longleftarrow \Longleftarrow \longrightarrow \Longrightarrow \longleftrightarrow \Longleftrightarrow \longmapsto \hookrightarrow \Join \blacksquare \bowtie \models \ncong % \cong produces the wrong symbol: it shows a dot on top of a plus, but there should be a ~ on top of = \cong \stopformula \stoptext