ðeɪ wɜːɹ ˌɪntɹədˈuːst baɪ æz ɐ dʒˌɛnɚɹəlᵻzˈeɪʃən ʌvðə kəszˈuːl ɹˌɛzəlˈuːʃən fɚðə kwˈoʊʃənt ˈɑːɹ slˈæʃ ˈɛks wˈʌn, ...., ˌɛksˈɛn ʌv ˈɑːɹ baɪ ɐ ɹˈɛɡjʊlɚ sˈiːkwəns ʌv ˈɛlɪmənts.
They were introduced by  as a generalization of the Koszul resolution for the quotient R/(x1, ...., xn) of R by a regular sequence of elements.