Nonnegativity constraints

Hi everyone,
I would like to impose nonnegativity constraints for some of the variables in my stochastic small open economy model. Can anyone help me about how to include/capture inequalities in the mod.file?
Thank you in advance for your interest.


Dear Meral,

I think that the best choice for you is to use the logarithm lx = log(x) of the variable instead of the variable x itself. The you have guaranteed that the variable x = exp (lx) i positive.