organized nodes, added quantifiers, updated axioms
finished, organized, axioms

TODO:
- uniqueness of axioms
- consequences of axioms
- move ordered pairs, relations, functions, etc to a new chapter
finished stating axioms

TODO:
- finish section Predicate Logic
- state union/intersection axiom theorems
- prove axiom theorems
- state & prove consequences
created setstructures branch

- created chapter 3
- moved ordered tuples, relations, functions, operations to chapter 3
- moved all old stuff from foundations.tex to chapters 2 and 3
updated axioms, added consequences
refactored variables in axioms
Merge branch 'reals-settheory' into reals-setstructures
Merge branch 'reals-setstructures' into reals