  If $s$ and $t$ are relatively prime J. Olsson proved in 2008 that the
$s$-core of a $t$-core partition is again a $t$-core partition, and that the
$s$-bar-core of a $t$-bar-core partition is again a $t$-bar-core partition.
Here generalized results are proved for partitions and bar-partitions when the
restriction that $s$ and $t$ be relatively prime is removed.
