Ladders and Squares

16.10.2025 11:30 - 13:00

L. Notaro (U Wien)

Given a positive integer \(k\), a \(k\)-ladder is a lower-finite lattice whose elements have at most \(k\) lower covers. In 1984, Ditor asked whether for every \(k\) there is a \(k\)-ladder of cardinality \(\aleph_{k-1}\). We show that this question has a positive answer under the axiom of constructibility.

Organiser:

KGRC

Location:

SR 10, 1. Stock, Koling. 14-16, 1090 Wien