Try some variants of the syntax in the enhanced calculator. In the previous example, the sq function has to end with two semicolons to close off both the while loop and the let statement, which is pretty clunky. Can you change the syntax to make it more intuitive? If you add closing symbols to conditional statements if/then/else/fi and loops while/do/done, can you make the syntax of statement lists more flexible?

In the last example, user functions evaluate all of the actual arguments, put them in a temporary array, and then assign them to the dummy arguments. Why not just do them one at a time and set the dummies as the actuals are evaluated?