"Remove from the value of HOOK the function FUNCTION.
HOOK should be a symbol, and FUNCTION may be any valid function. If
FUNCTION isn't the value of HOOK, or, if FUNCTION doesn't appear in the
-list of hooks to run in HOOK, then nothing is done. See add-hook."
+list of hooks to run in HOOK, then nothing is done. See `add-hook'."
(if (or (not (boundp hook)) ;unbound symbol, or
(null (symbol-value hook)) ;value is nil, or
(null function)) ;function is nil, then