Yes, and math has the notion of "free variable" and "bound variable" [1]. [1] https://en.wikipedia.org/wiki/Free_variables_and_bound_variables https://en.wikip

Yes, and math has the notion of "free variable" and "bound variable" [1]. [1] https://en.wikipedia.org/wiki/Free_variables_and_bound_variables https://en.wikipedia.org/wiki/Free_variables_and_bound_varia...