Upper panel: evolution of the mass fractions of light nuclides up to F (including also P) resulting from the specific SEP event of model C_a_03, i.e. of a C target irradiated by α-particles only with Φ_α = 10⁻¹¹ mb⁻¹ s⁻¹ and a constant-energy spectrum with E/A ≤ 3 MeV. Lower panel: same for model CNO_a_07, i.e. a CNO target irradiated by α-particles only with Φ_α = 10⁻¹¹ mb⁻¹ s⁻¹ and a constant-energy spectrum with 0 ≤ E/A ≤ 7 MeV. The hashed area corresponds to the irradiation time ranges considered to explain the P-rich abundances of both stars.