to the extent that the low estimation of provisional tax arises gen.

[drifting_along]

В этом предложении не уверена со смыслом provisional tax (предварительная налоговая ставка?) и не понимаю смысл начиная от to the extent

The Comissioner, acknowledging that provisional tax for 2012 was settled prior to the date of voting of the new law, discloses that he does not intend to impose additional tax for the year 2012 to the extent that the low estimation of provisional tax arises as a result of the amendment of the law.

еще контекст (о чем поправка) - amendment with regards to the restrictions imposed on tax losses carried forward and their offset

и еще ... Taxable income arising in 2012 may only be offset against taxable losses of 2007 onwards. Taxable losses up to and including 2006 can no longer be offset.

[Peter Cantrop]

смысл:
he does not intend - не намеревается
to impose additional tax - применить дополнительный налог
for the year 2012 - к 2012 году
to the extent that - поскольку
the low estimation of provisional tax arises - возникает низкий размер временного налога /или: временный налог приводит к понижению налоговых сборов
as a result of the amendment of the law - в результате поправки к закону.

[drifting_along]

Спасибо, так хоть что-то проясняется