Typo basics.tex : litle -> little
typo: Getzen
Merge pull request #478 from TimRichter/getzen

typo: Getzen
point view -> point of view (twice)
Merge pull request #477 from bjmprice/master

Typo basics.tex : litle -> little
Merge pull request #479 from TimRichter/pointview

point view -> point of view (twice)
type of ap_f in Lemma 2.2.1
Errata for 83d02ba, unmarked
mark errata for 83d02ba