Complex sentence: Evidently, there is a correspondence of a kind between wave functions and kets as defined by Cohen-Tannoudji, but they are different things, and many wave functions correspond to one ket as defined by Cohen-Tannoudji et al.
Split into simpler sentences: Evidently, there is a correspondence of a kind, not one-to-one, between wave functions and kets as defined by Cohen-Tannoudji, but they are different things. Many wave functions correspond to one ket as defined by Cohen-Tannoudji et al.