doubling a number

[Skaperen]

so there is nothing to do this already defined in some module; i must pass along this or some definition to do it? i don't think there will be exponentials but i am not 100% sure. my earliest worry when thinking about doing my own function was complex numbers. these will be typically more than 100 digits, possibly over 2000, but always in decimal. so, this function will have to check types or try/except everything.