"Fun trick 1" r(f) = outer(f,(x,y,z)) p(f) = -i hbar (d(f,x), d(f,y), d(f,z)) p2(f) = -hbar^2 (d(f,x,x) + d(f,y,y) + d(f,z,z)) Psi = psi(x,y,z,t) C = p2(r(Psi)) - r(p2(Psi)) "Verify equation (1)" check(C == -2 i hbar p(Psi)) "ok" "Verify equation (2)" T = p(p(r(Psi))) - r(p(p(Psi))) check(C == contract(T)) "ok" "Verify equation (3)" T = p(p(r(Psi))) - p(r(p(Psi))) + p(r(p(Psi))) - r(p(p(Psi))) check(C == contract(T)) "ok" "Verify equation (4)" I = ((1,0,0),(0,1,0),(0,0,1)) check(p(r(Psi)) - r(p(Psi)) == -i hbar Psi I) "ok" "Verify equation (5)" check(p2(Psi) == contract(p(p(Psi)))) "ok" Run