Various corrections, new set theory development as better examples.
Created by: SimonGuilloud
- Added kernel helper functions to instantiate schematic predicate or function in a whole sequent
- Corrected equivalence checker to deal correctly with empty disjunction (permits among other to use True and False in Rewrite)
- Inconsequential change in a small helper method "bindAll" so that it doesn't sort variables
- Small qol update in the function symbol definition in the running theory so that when verifying the definition of a new symbol, it checks the formulas with variables bound from left to right and from right to left.
- InstFunSchema and InstPredSchema weren't extending SCProofStep
- Corrected minor issues with axiom files of set theory (SetTheoryZAxioms, etc)
- New file with some development of set theory, in particular theorems regarding mapping/replacement on sets and cartesian product.
- Completed ElementsOfSetTheory so that it fills an actual theory.
- Improvement/Correction of various "tactics".