Plus have the same grammar, and so do
Sum. So is there a function doing multiplication that has the same grammar as
Total does then?
If yes, what is it? If no, why?
Now I learn from @AntonAntonov that there is less need to design a
ListProduct function. So this indicates that multiplication and addition cannot be treated on the same footing.
About "duplicate": I think not. Because my question is not aimed at finding how, but at why.
About "off-topic": I think it constructive to make some of the design "philosophy" behind clearer to facilitate deeper understanding.