Degeneracy between A_L and Σ₀ − 1, computed as a derived parameter in our (μ, η) parameterization. The horizontal dashed line includes ΛCDM (but is also marginalized over one of the two degrees of freedom in the μ–η space). The vertical dashed line shows A_L = 1. The filled contours use the Planck TT,TE,EE+lowE+lensing likelihood, alone and in combination with WL+BAO/RSD data. The unfilled contours show the constraints from Planck TT,TE,EE+lowE. Note that A_L only affects CMB lensing of the Planck power spectra by definition, as discussed in Sect. 6.2.