Revert "improvement in the omega function for usable rules"
Revert "improvement in the omega function for usable rules"

not sound after all

This reverts commit 34d937a9d792bbe33855de73b7ba9fc75e414cf7.

and disables checking of the computed usable rules

pepeiborra/narradar,pepeiborra/narradar,pepeiborra/narradar