[R] choosing constraints for function optim method="L-BFGS-B" when they are in terms of other parameter values

[Tom Stone]

I have a function of several variables which I wish to minimise over four
variables, two of the upper bounds for which are defined in terms of other
variables in the model over which minimisation will take place. I cannot
work out how to code this in such a way as to avoid getting an error message
when I run the code.

If anyone can provide any assistance I will be most grateful.

Best Regards

Tom Stone