Definition of "leftness"

In fact, early generative work recognized a leftness effect on pronoun antecedent relations (Langacker 1969) and the binding of pronouns by quantifiers and other operators (Postal 1972, Jacobson 1977, Chomsky 1976).

1995, Mary Dalrymple, Formal Issues in Lexical-functional Grammar, page 254

The clockwise beating of cilia results in a net flow of extraembryonic fluid leftwards, which may result in the accumulation of an unidentified leftness determinant, which flows into the node symmetrically, on the left side of the node.

2006, Manfred Schliwa, Molecular Motors, page 359