"Verify solution (1)" psi = exp(-i / hbar (E t - px x - py y - pz z)) E = sqrt(px^2 c^2 + py^2 c^2 + pz^2 c^2 + m^2 c^4) T = d(psi,t,t) / c^2 - d(psi,x,x) - d(psi,y,y) - d(psi,z,z) + m^2 c^2 / hbar^2 psi check(T == 0) "ok" Run