complex-numbers: naming inconsistencies

I am currently creating method stubs for Exercises and when working on the compley-numbers exercise I've noticed an inconsistency in the naming of some methods: The methods are sometimes named after the mathematical operators and sometimes after established function names in programming.

An example of that are the Operators + and -. + is named add while - is named minus.

With the method stubs it will be clear which method is responsible for which action but I still think that the naming convention should be unified for increased clarity.

Personally I like the usage of already established names, so I would propose the following name refactorings:

  • +: add -> add (no change)
  • -: minus -> sub
  • *: times -> mult / mul
  • /: div -> div (no change)
  • e^x: exponentialOf -> exp