Locality and (minimal) search

Locality can be stated declaratively, a goal being closest when no other potential goal c-commands it (2), or procedurally, as the order in which a probe considers the nodes of its search space, stopping at the first match. Depth-first search, left to right, can match a goal that another potential goal c-commands (7a); breadth-first search matches the c-commanding goal (7b), and in general a potential goal c-commanding the goal it matches can only be that goal's sister. On a right-branching search space the two orders coincide (8). Smuggling favours depth-first search: the theme in a fronted participle phrase and the agent below it are equally deep, so breadth-first search cannot prefer the theme (9).

Implementation notes

• A search order is a key on positions, and the node a search matches is the one the probe finds under that key (Probe.Finds), the search orders of Probe/Search.lean.
• The tree of (7) is the figure's, with arbitrary leaves. That of (9) is Collins2005's passive at the stage where Infl probes, PartP in Spec,VoiceP, and its potential goals are its DPs.

TODO

• The chapter's third search algorithm, which searches a specifier exhaustively yet satisfies (2); interaction and satisfaction (section 22.3); the shape of the search space (section 22.4).

References

• Branan & Erlewine 2026, Locality and (minimal) search
• Collins 2005, A Smuggling Approach to the Passive in English formalized