cl-first

cl-first is an alias for `car' in `cl-lib.el'.

(cl-first LIST)

Return the car of LIST. If arg is nil, return nil.
Error if arg is not nil and not a cons cell. See also `car-safe'.

See Info node `(elisp)Cons Cells' for a discussion of related basic
Lisp concepts such as car, cdr, cons cell and list.