double check of steady state in steady_

[lombard]

In steady_ you find the following set of commands

if isfield(options_,'unit_root_vars')
if isempty(options_.unit_root_vars)
cheick = max(abs(feval([M_.fname '_steadystate'],...
oo_.steady_state,...
[oo_.exo_steady_state; ...
oo_.exo_det_steady_state]))) >
options_.dynatol ;
end
end

It seems that the maximum absolute value of the variables in the steady state is compared with the options_.dynatol.

What is the meaning of this check?

Regards

Gianni