cl-progv is an autoloaded Lisp macro in `
(cl-progv SYMBOLS VALUES &rest BODY)
Bind SYMBOLS to VALUES dynamically in BODY.
The forms SYMBOLS and VALUES are evaluated, and must evaluate to lists.
Each symbol in the first list is bound to the corresponding value in the
second list (or to nil if VALUES is shorter than SYMBOLS); then the
BODY forms are executed and their result is returned. This is much like
a `let' form, except that the list of symbols can be computed at run-time.