### Two inequalities between cardinal invariants

by Raghavan and Shelah. [RaSh:1060]

Fundamenta Math, 2017

We prove two ZFC inequalities between cardinal invariants.
The first inequality involves cardinal invariants associated
with
an analytic P-ideal, in particular the ideal of subsets of
omega of aymptotic density 0 . We obtain an upper bound on
the ast-covering number, sometimes also called the weak covering
number, of this ideal by proving in Section 2 that cov {ast}
({Z}_0) <= {d} .
In Section 3 we investigate the relationship between
the bounding and splitting numbers at regular uncountable cardinals.
We prove in sharp contrast to the case when kappa = omega, that
if kappa is any regular uncountable cardinal, then
{s}_kappa <= {b}_kappa .

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