These mathematica files validate the perterbative elasticity solution for a compressible neo-Hookean elastic layer growing equi-biaxially on a compressible infinite neo-Hookean substrate discussed in Section VI of "Pattern selection when a layer buckles on a soft substrate" by Cheewaruangroj and Biggins.

compressible_wrinkle_validate.nb is a human-readable matheamtica file, which the user should open and run from top to bottom. Instructions are in the notebook itself. 

In more detail, the notebook compressible_wrinkle_validate.nb

1) Computes each term in the series expansion of the bulk and boundary equations,
2) Calls the other mathematica notebooks in this file as input to load the full series solutions for the bulk equations for a given choice of parameters,
3) Solve for the constant of integrations,
4) Verifies numerically that the series solutions indeed satisfy the bulk and boundary equations,  
5) Calculates the stability threshold and the Landau energy coeficients to characterize the instability.

for hexagonal buckling patterns, leading to the results for the energy coefficients given in the main manuscript.



