Half-mission lensing reconstructions tests for the gradient (ϕ; upper) and curl (Ω; lower). Blue points show reconstruction power spectra from SMICA half-mission difference maps, after multiplication by a factor of 20. The orange points show the auto-spectrum of the reconstruction built from HM₁ and HM₂ (with no noise mean field), and the green points the cross-spectrum of the reconstruction built from HM₁ with that built from HM₂ (with no noise contribution to the reconstruction noise N⁽⁰⁾). The black line in the upper plot shows the Planck TT,TE,EE+lowE+lensing best-fit spectrum.