Comments on “Supersolvable frame-matroid and graphic-lift lattices” by T. Zaslavsky [European Journal of Combinatorics 22 (2001) 119]

To characterize supersolvable frame matroids, Zaslavsky, in his 2001 paper “Supersolvable frame-matroid and graphic-lift lattices”, utilizes a classification of their modular copoints. Unfortunately, one type of modular copoint is missing in the classification. We correct the modular copoint theorem and show that the supersolvability theorem is not affected, while giving a simpler proof.