Fig. 1. (a) Four-soliton molecule expressed by Eq. (25) with Eqs. (30), (40), (42) and N = n = 4 at time t = 0. (b) Same as in (a) but at t = 15.

Fig. 2. The interaction between one soliton and one three-soliton molecule for the field u given by Eq. (25) with Eqs. (30), (40), (43), N = 4, and n = 3 at time t = 0.

Fig. 3. (a) Few cycle soliton structure expressed by Eq. (48) with c = 4 at time t = 0. (b) Envelope soliton structure expressed by Eq. (48) with c = 50 at time t = 0. (c) Periodic kink given by Eq. (49) with c = 0.5 at time t = 0. (d) Kink–kink molecule given by Eq. (50) with c = 0, k₁ = –1, k₂ = –2, and x₀ = 8. (e) Kink–kink molecule given by Eq. (50) with c = 0.06, k₁ = –1, k₂ = –2, k = 5, and x₀ = 10 at t = 0. (f) PK–APK molecule given by Eq. (51) with x₀ = y₀ = –c = –5 and c₁ = 0.1 at time t = 0.