The example below compiles with latest ConTeXt, suggesting that the Unicode quadruple symbol ⨌ has not been registered as a math symbol, as the command it is set to is ignored. \setupbodyfont[xits,10pt] \setupmathematics[integral=nolimits, lcgreek=normal, default=normal] \appendtoks \catcode`∫=\activecatcode \letcharcode `∫ \int \catcode`∬=\activecatcode \letcharcode `∬ \iint \catcode`∭=\activecatcode \letcharcode `∭ \iiint \catcode`⨌=\activecatcode \letcharcode `⨌ \undefined \to \everymathematics \starttext \startformula ⨌_𝐴 𝑓(𝑥)\, d𝑥 = ∫_𝐵 ∭_𝐶 𝑓(𝑡, 𝒙)\, d𝑡 d𝒙 \stopformula \stoptext