"Problem 15.1.1" "Verify commutator" ahat(f) = sqrt(1/2) (f xi + d(f,xi)) ahatdag(f) = sqrt(1/2) (f xi - d(f,xi)) C = ahat(ahatdag(psi(xi))) - ahatdag(ahat(psi(xi))) check(C == psi(xi)) "ok" Run