Chemical abundances ([α/Fe], [Na/Fe], and [Al/Fe]) of the GALAH sample with |L_Z|< 600 kpc km s⁻¹. In the top panels, the dashed blue line indicates the division based on [α/Fe], separating stars into low −α (left) and high-α (right) sequences. Red squares and triangles in the left column mark low-α, high-Na (LAHN) stars. The dashed blue box in the middle left panel outlines this selection. A representative median error is shown.