begin thorn SimpleWaveScript

begin variables
    phi pi
end variables

begin temporaries
    foo bar
end temporaries

begin derivatives
    Du u_i = (u_(i+1) - u_(i-1))/h
    Dv v_i = (v_(i+1,j) - u_(i-1,j))/h
end derivatives

begin calculation initial_sine_calc scheduled at initial
  phi = sin(2*PI*(x-t))
  pi = -2*pi*cos(2*PI*(x-t))
end calculation

begin calculation calc_rhs scheduled at mol_calcrhs
  D_t phi = pi
  D_t pi = Euc^ij*D_ij phi
end calculation

end thorn