fix 6.10.12, close #574 and #577
fix section 8.1 to match new 6.10.12
an exercise for the other definition of Z
unmarked errata for de14e6b
one more erratum
yet another erratum
improve notation
Merge branch 'master' into integers

Conflicts:
	errata.tex
fix typos, close #595
unmarked errata for 4818f12
Merge pull request #596 from mikeshulman/lemma6.12.4

fix typos, close #595
Mark Errata (auto)
Merge pull request #583 from mikeshulman/integers

fix 6.10.12, close #574 and #577
Mark Errata (auto)
Merge remote-tracking branch 'upstream/master' into parenthesis

Conflicts:
	hits.tex

sync with upstream
switched from '.)' to ').'