And use it to define negate and add for Complex numbers in a way that is independent of component types. Also add a bigint type and verify that pocomath will then handle Gaussian integers "for free".
No negation (and therefore no subtraction) since that needs self-reference.
And implement negate on numbers, and use dependencies to define subtract. Co-authored-by: Glen Whitney <glen@studioinfinity.org> Reviewed-on: #2
