ðə mˈɑːdʒuːlz ænd ɑːɹ ɹˌɛpɹᵻzˈɛntˈeɪʃənz ʌvðə jˌuːnɪvˈɜːsəl ɛnvˈɛləpɪŋ ˈældʒᵻbɹə ænd ɪts sˈɛntɚɹ ˈækts ɔnðə mˈɑːdʒuːlz baɪ skˈeɪlɚ mˌʌltɪplɪkˈeɪʃən ðɪs fˈɑːloʊz fɹʌmðə fˈækt ðætðə mˈɑːdʒuːlz ɑːɹ dʒˈɛnɚɹˌeɪɾᵻd baɪ ɐ hˈaɪɪst wˈeɪt vˈɛktɚ.
The -modules  and  are representations of the universal enveloping algebra  and its center acts on the modules by scalar multiplication (this follows from the fact that the modules are generated by a highest weight vector).