Hi Taco,
This should normally work, but it depends on the current math encoding (see the math-xxx.tex files in the distribution):
\definemathcharacter [+] [ord] [mr] ["2B] % [bin] is default
Just tried this but to no avail :-( It seems like the definition isn't found at all: --- \def\ket#1{\lvert#1\rangle} \startmathcollection[default] \definemathcharacter [myplus] [ord] [mr] ["2B] \stopmathcollection \starttext Note the spacing in \startformula \startmathalignment \NC\ket{+}\NR \NC\ket{++}\NR \NC\ket{+++}\NR \NC\ket{++++}\NR \NC\ket{\myplus\myplus\myplus\myplus}\NR \NC\ket{000}\NR \stopmathalignment \stopformula \stoptext --- Is this caused by some wrong math encoding scheme? Or is there something else that I miss? Puzzled, Oliver