Found:

Adjunction

**SYNTAX: ** one of the two types of **movement** operation, the other being **substitution**. Traditionally, there are two types of adjunction: Chomsky-adjunction, which results in a structure like (i), and sister-adjunction, which results in a structure like (ii). Both structures are the result of adjunction of X to Y^{i+1}, but only in (i) the node adjoined to is doubled, or split into two **segment**s to accommodate the adjoined element.

(i) YUnder the assumption of the^{i+1}(ii) Y^{i+1}/ \ / | \ X Y^{i+1}X Z Y^{i+1}/ \ Z Y^{i}

LIT. | Chomsky, N. (1986b) Chomsky, N. (1986b) Kayne, R. (1984) |