This product can be computed beginning with any of the parameters in the list. The number may be a literal value or a scalar. With this device, you can make your model command independent of the size of the model, and you can accommodate a model of any size. Only the namelists would have to be changed from one specification to another. The last expression is the one being minimized, so it does not have a name.
Any expression can use the name of any previous expression, as many times as desired.
This may bring enormous gains in simplifying expressions. Note that functions are compiled from left to right. That means if you try to use a name which is defined after the function you are defining, an error will occur in which the name you are using does not appear to be defined. This provides sufficient accuracy to obtain appropriate solutions to the problems. The subfunctions defined as above may be the derivatives of the function you are optimizing.