Why are some of the disconnected letters considered a complete verse, such as "Alif, Lam, Mim," while some are considered part of a verse, such as "Alif, Lam, Ra"? And what is the correct recitation of the letters "Alif, Lam, Ra"?

The counting of Quranic verses is a divinely established science, leaving no room for ijtihad (definition) (independent reasoning). The Kufans considered some of the opening letters of surahs as individual verses, such as: {وَالْفَجْر} (Al-Fajr), {وَالضُّحَى} (Ad-Duha), {وَالْعصر} (Al-Asr), {ألم} (Alif, Lam, Mim), {ألمص} (Alif, Lam, Mim, Sad), {طه} (Ta, Ha), {يس} (Ya, Sin), and {حم} (Ha, Mim). As for the rules of prolongation (madd) and shortening (qasr) in the opening letters of surahs, they do not differ from other parts of the Quran. What has a reason for prolongation is prolonged, and what does not have a reason is not extended beyond the natural prolongation.