anchor.diff:    ! Numerics
     double precision :: pi, dt
     double precision :: au, ar, botDrag
  -  double precision :: ah(layers)
  +  double precision :: ah(layerwise_input_length)
     double precision :: slip
     double precision :: hmin
     integer nTimeSteps
  
positive.code: program MIM
    implicit none
  
    integer, parameter :: nx = 300 !< number of x grid points
    integer, parameter :: ny = 300 !< number of y grid points
    integer, parameter :: layers = 2 !< number of active layers in the model
  
negative.code:   double precision :: thickness_error
  
    ! Model
    double precision :: hmean(layerwise_input_length)
    ! Switch for using n + 1/2 layer physics, or using n layer physics
    logical :: RedGrav
  
  