Left: reconstruction of the angular diameter distance d_A(z) from the mock Euclid data with the GA approach. The dashed black line is ΛCDM, the solid red line is the GA fit and the shaded region corresponds to the 1σ GA errors. Centre: results on the distance modulus μ(z) from the mock Euclid+LSST+DESIRE data with the GA approach. The dashed line at zero is ΛCDM, the red line is the GA fit and the shaded region corresponds to the 1σ GA errors. For clarity, we only show one thousand of the total SnIa points. Right: reconstruction of the η(z) parameter in the range z ∈ [0.9, 1.6]. In all cases the error bars of the data points correspond to 1σ uncertainty.