This GPCVN-Logo ( Gradual Permanent Curve Negative - for Logographic Languages ) is designed to depict states which the change from one 'normal' state to an alternative 'abnormal' state is irreversible and therefore permanent.  e.g.   The food is fresh.  It is starting to loose its freshness. It is going off. It has gone off.  It is going rotten. It is starting to decompose. It is decomposing ( and it ain't coming back ! )