Just pair‐merge

AbstractTwo structure‐building operations are currently posited in minimalist theory: an operation forming sets (set merge), and an operation forming ordered pairs (pair‐merge). I argue that pair‐merge is sufficient to generate syntactic relations, so set merge, also called simple merge, should be eliminated from syntactic theory on grounds of simplicity. This conclusion requires reevaluating the relationship between structure‐building and labeling of constituents for the expression of syntactic relations, because labeling plays a crucial role in this comparison of theories according to the simplicity metric. An existing labeling hypothesis, specifically Chomsky's Labeling Algorithm, is shown not to have any advantage claimed for it by comparison with the just pair‐merge hypothesis proposed here. An advantage of the only pair‐merge hypothesis is that it provides a more principled origin for the inherent asymmetry in the c‐command relation that does not follow from a theory that includes set merge.