lax-plist-get

lax-plist-get is a built-in function in `C source code'.

(lax-plist-get PLIST PROP)

Extract a value from a property list, comparing with `equal'.
PLIST is a property list, which is a list of the form
(PROP1 VALUE1 PROP2 VALUE2...). This function returns the value
corresponding to the given PROP, or nil if PROP is not
one of the properties on the list.