44. What is incorporation and what are its conditions?
45. In what cases is it permissible to incorporate and not to incorporate?
46. When is it impermissible to incorporate?
44. Incorporation is when two identical letters are joined together. Its conditions are that the two letters are next to each other and the first one does not have a vowel sign while the second one does, and if the first letter has a vowel sign or is preceded by an alif, its vowel sign is erased. For example: مادَّ which was originally مادَدَ. If the first letter is preceded by a sound letter without a vowel sign, the vowel sign of the first letter is given to the letter preceding it. For example: یَمُدُّ which was originally یَمدُدُ.
45. It is permissible to incorporate and not to incorporate in two cases: One, in a singular aorist tense verb in the jussive state, as in لَم یَمُدُّ or لَم یَمدُد. The second case is in a singular command verb, as in مُدُّ or اُمدُد.
46. It is impermissible to incorporate when the verb is connected to a sound nominative pronoun with a vowel sign, for example: مَدَدتُ.