Functional analysis MOC Dirac orthonormality A set of kets |ππβ© where π ββ is said to be Dirac orthonormal1 iff fun β¨ππβ²|ππβ²β©=πΏ(πβπ) where πΏ is the Dirac delta, and in addition complete iff β«π·|ππ§β©β¨ππ§|ππ§=π develop | en | SemBr Footnotes 2018. Introduction to quantum mechanics, Β§3.3.2, p. 100 β©