"Problem 15.5.1" "Verify commutator" ahat(f) = sqrt(1/2) (f xi + d(f,xi)) ahatdag(f) = sqrt(1/2) (f xi - d(f,xi)) xihat(f) = sqrt(1/2) (ahatdag(f) + ahat(f)) pihat(f) = i sqrt(1/2) (ahatdag(f) - ahat(f)) C = xihat(pihat(psi(xi))) - pihat(xihat(psi(xi))) check(C == i psi(xi)) "ok" Run