Dmitry Kozlov
We reprove and generalize in a combinatorial way the result of A. Bjőrner [J. Comb. Th. A ${\bf 30}$, 1981, pp. 90–100, Theorem 3.3], that order complexes of noncomplemented lattices are contractible, namely by showing that these simplicial complexes are in fact nonevasive, in particular collapsible.