Dear Bob More corrections and clarifications to ttt and ctcs. The former are all from Fer-Jan de Vries and the latter are all from Al Vilcius (a former student of Joan's who now works for CIBC and has read ctcs with an eagle eye). %%%%%%%%%%%%%%%%%%%%%%%%%%%%% ttt %%%%%%%%%%%%%%%%%%%%%%%%% \item\lb p. 139\rb (F-J de Vries) l. -3: "subststantially" should read like "substantially" \item\lb p. 140\rb (F-J de Vries) l. 9: "Kiesler" should be "Keisler" \item\lb p. 168\rb (F-J de Vries) l. -15: "Kiesler" should be "Keisler" \item\lb p. 183\rb (F-J de Vries) l. -7: Kock \lb 1982\rb should be Kock \lb 1981\rb (SDG) \item\lb p. 267\rb (F-J de Vries) l. 267: "Mikkelson" should be "Mikkelsen" \item\lb p. 337\rb (F-J de Vries) "Mikkelson" should be "Mikkelsen" \item\lb p. 338\rb (F-J de Vries) "J.Shonfield" should read as "J.R. Shoenfield" Two additional references (F-J de Vries): H. Cartan and S. Eilenberg, {\bf Homological Algebra}. Princeton University Press, 1952. Anders Kock, {\bf Synthetic Differential Geometry}. London Mathematical Society Lecture Note Series 51. Cambridge University Press, 1981. %%%%%%%%%%%%%%%%%%%%%%%%%%%%%% to ctcs %%%%%%%%%%%%%%%%% \item\lb p. 79\rb (Al Vilcius). l. 7: replace ``$\id_i$'' by $\id_{D_i}$. \item\lb p. 87\rb (Al Vilcius). In Theorem 4.2.20, l. 2 replace ``$\Csc$'' by ``$\Gsc$'. In the last line replace ``$\Mod(\Gsc,\Csc)$'' by ``$\Mod(\Gsc,\Dsc)$''. \item\lb p. 103\rb (Al Vilcius). Change ``set'' to ``collection'' in the second line of 4.6.2 and the sixth line of 4.6.3. (We are using ``collection'' as an informal synonym for ``class'', without getting into set theory.) At the end of the first paragraph of 4.6.3, add the following: ``We write $M:\Ssc\to\Csc$ for such a model. This use of the same symbol to denote both the sketch homomoprhism and the graph homomorphism is a bit of notational overloading that in practice is always disambiguated by context.'' \item\lb p. 108\rb (Al Vilcius). Change ``set'' to ``collection'' in line 3 of 4.7.2. \item\lb p. 208\rb (Al Vilcius). Top diagram should have a $B$, not $C$ in the SE corner. The fourth line should say that $p_2$, not $p_1$ is the pullback of $f$ along $g$. \item\lb p. 228\rb (Al Vilcius). last line: Word ``be'' is missing. \item\lb p. 255\rb (Al Vilcius). l. -5. Replace ``cleavage'' by ``opcleavage''. \item\lb p. 256\rb (Al Vilcius). l. -8, the expression has misplaced brackets. Should be ``$$Fg\lb Ff(u)\rb (Al Vilcius).\o\kappa(g,Ff(X))\o\kappa(f,X)$$'' l. -2 should be ``functors $\Csc\op\to\Cat$.'' \item\lb p. 258\rb (Al Vilcius). Definition 11.2.3, GS--1 should be ``object of $G_0(\Csc,F)$''. \item\lb p. 259\rb (Al Vilcius). l.8 should read ``$x'=Ff(x)$''. In paragraph starting line 11, orientation of $G_0(\Csc,F)$ requires the functor $G_0(F)$ to be the projection on the second coordinate, not first. \item\lb p. 261\rb (Al Vilcius). In Theorem 11.2.9 first projection should be second as above. \item\lb p. 264\rb (Al Vilcius). In Definition 11.3.4, FI--1, replace ``P:\Esc\to\Cat'' by ``$P:\Esc\to\Csc$''. Regards, Mike