Historically, the least solution to the data flow equations is called the MFP solution (for Maximal Fixed Point) althout it in fact computes the least fixed point; the reason is that the classical literature tends to focus on analyses where $square-cup$ is $intersection$ (and because the least fixed point with respect to $square-image-of-or-equal-to$ or $superset-of-or-equal-to$ then equals the greatest fixed point with respect to $subset-of-or-equal-to$)

Nielson, Flemming, Hanne R. Nielson, and Chris Hankin. Principles of program analysis. Springer, 2015.