Deletes associations from the associative list. See Associative lists.
| elt | An instance of <object>. The key element of an association to remove. |
| alist | An instance of <sequence>. An associative list. |
| key: | An instance of <function>, used to obtain a key element from an association. The default is head. |
| test: | An instance of <function>, used to compare keys. The default is =. |
| new-alist | An instance of <sequence>. The new associative list. |