product ? *** and sum ? ***

[parisse]

If arg3 and arg4 are not integers, product behaves like if you input a list of values, it makes the product of the elements of the list. I'm going to modify product:
- if the argument is a list (with [] or {} delimiters) or does not have 5 args, no change
- if the argument is a sequence with 5 arguments, do what you want