... x1 = l1+l2+…+lN x1 Waves in Fluids and Solids 80(4)(4) (4)(4) (4)33 11431 (12) (12) (12) (12) (12) 33 2143201, ,4exp[ ( ) ] 5, ,12 16exp[ ( ) ] 13, ,20qnnn nn ... surfaces strings number 15 and 16 in expressions (35) must be replaced with: Waves in Fluids and Solids 86Here A(n) and B(n) are six unknown coefficients of the linear combination. Together ... for surface waves in layers with varying thickness, J. Math. Anal. Appl. 21 (1968) 431 – 441. Waves in Fluids and Solids 64Proof a) flows out from considering the right-hand-side of (6.1),...