(8). (The subscripts on the NPs in (8) are notational conveniences so we can tell the mapart.)^20
Theapplicationofa derivationalrulecanthus benotatedas an orderedpairoftrees. Alternativelyitcanbeabbreviated
in a single tree, say like (9).
As section 1.7 mentioned, since the middle 1970s (e.g. Chomsky 1975) it has been assumed that movement rules
always leave behind a“trace,”a sort of unpronounced pronoun, whose antecedent is the moved constituent. In this
notation, theapplicationoftherulecanbenotatedas (10),wheretis thetrace,and thesubscriptsshowtherelationship
between the trace and its antecedent. (10) can be thought of roughly as that movie, Dave disliked (it), where the
parenthesized pronoun is not pronounced.
The reason I call the two structures related by (8)“more underlying”and
46 PSYCHOLOGICAL AND BIOLOGICAL FOUNDATIONS
(^20) In the interest of paring things down to the essentials, I have again omitted many generally accepted details of structure in (8).