Hi together,
I've experienced a problem with \blackboard{} command. Please paste the following code and compile it (I have newest CTX beta version (updating daily)):
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\starttext
Variation 1:
$\forall n \in \blackboard{Z} \neq 0$: should be $0$
Variation 2:
$\forall n \in \integers \neq 0$: is $0$
\stoptext
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When the first variation is used, CTX seems to convert every folowing letter into blackboard characters within the rest of the math environment no matter where \blackboard brackets are placed.