Function: set-variable

Set VARIABLE to VALUE. VALUE is a Lisp object.
VARIABLE should be a user option variable name, a Lisp variable
meant to be customized by users. You should enter VALUE in Lisp syntax,
so if you want VALUE to be a string, you must surround it with doublequotes.
VALUE is used literally, not evaluated.

If VARIABLE has a `variable-interactive' property, that is used as if
it were the arg to `interactive' (which see) to interactively read VALUE.

If VARIABLE has been defined with `defcustom', then the type information
in the definition is used to check that VALUE is valid.

With a prefix argument, set VARIABLE to VALUE buffer-locally.