4FEffect of alterations in penalties

4F  Effect of alterations in penalties  (1) Where a provision of a law of the Commonwealth increases the penalty or maximum penalty for an offence, the penalty or maximum penalty as increased applies only to offences committed after the commencement of that provision.  (2) Where a provision of a law of the Commonwealth reduces the penalty or maximum penalty for an offence, the penalty or maximum penalty as reduced extends to offences committed before the commencement of that provision, but the reduction does not affect any penalty imposed before that commencement.