Propagation diagram of a 4G model having M_* = 0.47 M_⊙, lq_core = −0.25, lq_env = −2, X(He)_core = 0.9, and modes ℓ = 1 ranging from radial order k = 1 to 70. The logarithm of the square of the Brunt-Väisälä frequency (log N²) is depicted in blue and the logarithm of the square of the Lamb frequency for ℓ = 1 (log L₁²) in green. The red dotted vertical line is the lq_core (core-mantle) transition, and the orange dotted vertical line is the lq_env (mantle-envelope) transition. Red horizontal lines are the log(σ²) of each mode and red dots indicate the radial node positions in log(q).