Here we summarize small corrections ¡­

Here we summarize small corrections in Convexity notes. NOTE: an updated version is on the web page. The corrections: (1) Prop.2.3.2(ii) "convex comb." should be "nonnegative comb.", (2) A sentence has been added in the proof of Theorem 3.2.5 "We claim ...". (3) Proof of Theorem 4.4.4: the cone A was renamed, and a typo (y^Tz_j <0) was corrected, and the set C in the last paragraph was rewritten.