  Let M be a family of sequences (a_1,...,a_p) where each a_k is a flat in a
projective geometry of rank n (dimension n-1) and order q, and the sum of
ranks, r(a_1) + ... + r(a_p), equals the rank of the join a_1 v ... v a_p. We
prove upper bounds on |M| and corresponding LYM inequalities assuming that (i)
all joins are the whole geometry and for each k<p the set of all a_k's of
sequences in M contains no chain of length l, and that (ii) the joins are
arbitrary and the chain condition holds for all k. These results are q-analogs
of generalizations of Meshalkin's and Erdos's generalizations of Sperner's
theorem and their LYM companions, and they generalize Rota and Harper's
q-analog of Erdos's generalization.
