CAS grad() function

[Han]

Arguments that are optional are shown with []'s surrounding the argument. As an example, look at the arguments for the input() command. The help for grad() does not show any arguments surrounded by []'s. So I took that to mean that the list of variables is required. By specifying all variables (in the list), then one obtains the gradient (which is basically a list of all partial derivatives). On the other hand, specifying only a (proper) subset of all the variables then one obtains a list of partial derivatives. This was how I interpreted the help text.