User:ThaesOfereode/Schmidt–Hackstein's law

Schmidt–Hackstein's law is a Proto-Indo-European sound law that causes the language's laryngeal consonants – ', ', and  – to be deleted in certain contexts. In short, when a laryngeal consonant is preceded by any other consonant at the end of a syllable and followed by a consonant cluster, the laryngeal is dropped altogether. The law is named after German linguists Gernot Schmidt, who first described the law in 1973 and considered it a development unique to Proto-Indo-Iranian, and Olav Hackstein, who demonstrated its presence in the earlier Proto-Indo-European language in 2002.

History
Gernot Schmidt first described the law in 1973 in a paper entitled "The Iranic words for 'daughter' and 'father' and the reflexes of the interconsonantal H in the Indo-European languages". In it, he discusses the many forms of the term 'daughter' in the Indo-Iranian languages and discusses that they could not be reconciled with a single Proto-Indo-European form without an additional rule. To explain, there were four distinct derivations in the Indo-Iranian daughter languages: Sanskrit attested only a single form – दुहिता – while the Iranic languages had three distinct forms: *dugdar- (attested in Gathic Avestan 𐬛𐬎𐬔𐬆𐬛𐬀𐬭 ), *duxθrī (cf. Old Persian *duhçī-, attested in Modern Persian دوشیزه  'young girl, miss'), and *duxtar (attested in Modern Persian دختر  'daughter').

Based on the absence of Bartholomae's law, Schmidt determined that the latter two reflexes could not have derived from the Proto-Indo-European form  directly. Instead, he believed they must have come from a later ', arguing that the laryngeal sound was dropped and the ' was devoiced by regressive assimilation. Schmidt argued that the cluster of CHCC – where "C" represents any consonant and "H" represents any laryngeal consonant – was thereby reduced to a simpler pronunciation of CCC. Although ' itself would not be subject to the rule in its nominative form, as its most complex cluster is CHC, it was likely changed in that form as well based on analogy with oblique forms that did undergo the process, such as the genitive singular form ' which includes the CHCC cluster .

In 2002, Olav Hackstein revisited the sound change in a paper entitled "PIE *CH.CC > *C.CC" (Uridg. *CH.CC > *C.CC).

Overview
The law affects the laryngeal consonants of the Proto-Indo-European language – ', ', and  – which in turn generally affects the vowel realization in the daughter languages. In the descendant languages, there are some instances were