"Canonical commutation relation" X(f) = x f P(f) = -i hbar d(f,x) X(P(psi(x,t))) - P(X(psi(x,t))) X(f) = outer((x,y,z),f) P(f) = -i hbar d(f,(x,y,z)) X(P(psi(x,y,z,t))) - P(X(psi(x,y,z,t))) "Momentum space" X(f) = i hbar d(f,p) P(f) = p f X(P(psi(p,t))) - P(X(psi(p,t))) X(f) = i hbar d(f,(px,py,pz)) P(f) = outer((px,py,pz),f) X(P(psi(px,py,pz,t))) - P(X(psi(px,py,pz,t))) Run