Li vs. age for the Sun (⊙) and HIP 56948 (square) based on our NLTE Li abundances and isochrone ages, and for 16 Cyg B (filled circle) and 18 Sco (triangle, 2.7 Gyr), based on similar quantities by Ramírez et al. (2011) and Meléndez et al. (2012, in prep.). The total error bar ( ± σ) of the Li abundance is about the size of the symbols, while the error bars in age are shown by horizontal lines. For comparison we show the models by Charbonnel & Talon (2005); do Nascimento et al. (2009); Xiong & Deng (2009); Denissenkov (2010), shifted in Li abundance by 0.00,  − 0.03,  − 0.15,  − 0.05 dex, respectively, to reproduce our observed NLTE solar Li abundance. The age of HIP 56948 based on Li tracks is in perfect agreement with the age obtained from isochrones.