ungrab_key(+Key, +ModifiersMask, +UngrabWindow)
Releases the passive grab started by the key combination on the specified window if it was grabbed by this client. Has no effect on an active grab.
Key is the key that should be ungrabbed. One of:
ModifiersMask is one of:
modifiers_mask/2is useful to translate between modifier specifications and bitmasks.
UngrabWindow is the ProXL window where the grab is in effect.