Alist chains

An alist chain is a list containing property alists.

The set of all properties that will apply to a grob is typically stored as an alist chain. In order to find the value for a particular property that a grob should have, each alist in the chain is searched in order, looking for an entry containing the property key. The first alist entry found is returned, and the value is the property value.

The Scheme procedure chain-assoc-get is normally used to get grob property values.