Do a bit less in rules.tidyAlgebra.
Flag algebra rules as either algebra or both algebra and basic.
Make the value of the internal "facts" variable more useful.
Fix indentation from previous change.
New sample proofs.
Make a real Fact object for facts
Remove uses of "formula" in rule descriptions.
Make hints take priority over formulas for generating menu items.
Rationalize some rule descriptions.
Reformat fact collections as maps for easier identification
of the functions in the Chrome debugger.
Split facts into logic and algebra groups.
Work on rule labels; clean up some of label generation; add a fact.
Switch step editor to support several categories of rules, notably "algebra".
Remove findTypeRewriter and repeatedlyRewrite.