[NTG-context] Malicious little bugger

All, Came across this again. \placeformula[-] \startformula [9,\infty)=\{x:\,x\ge 9\} \stopformula Got it to compile with: \placeformula[-] \startformula\relax [9,\infty)=\{x:\,x\ge 9\} \stopformula Yuk!