[NTG-context] Multi-letter words/identifiers in math

Dear list, I am trying to typeset some multi-letter words/identifiers in mathematical formulas. Currently, doing things like `{\it variable}` or `{\mathit variable}` under math mode will cause the engine to shift all characters into the corresponding unicode mathematical alphanumeric block

[NTG-context] ConTeXt mathematics macros

looking for a "battery included" math module, which provides predefined macros like the absolute value symbol, derivative, and partial derivative. Any recommendation or advice on this? Thanks! Shuxian Wang _