1.AdverbFrom the time when a law, legal right or decree, contract, ownership interest, partnership (etc.) comes into force. .mw-parser-output .defdate{font-size:smaller}
"As the Act was passed without the required quorum, the constitutional court struck down the Act and declared it to be void ab initio"
2.AdverbCalculated from first principles, i.e. from basic laws without any further additional assumptions.