In mathematical logic, Morley rank, introduced by {harvs|txt=yes|authorlink=Michael D. Morley|first=Michael D. |last=Morley|year=1965}, is a means of measuring the size of a subset of a model of a theory, generalizing the notion of dimension in algebraic geometry. ==Definition== Fix a theory T with a model M. The Morley rank of a formula φ defini...