exception particles (حُرُوفُ الِاسْتِثْنَاء)
أصول الفقه
التعريف :
These are twelve words indicating that what comes after any of them is excepted from what comes before it. These words are: illā, ghayr, balh, siwā, siyyamā, khalā, Ꜥadā, ḥāshā, mākhalā, māꜤadā, laysa, lāyakūn.