This is a list of typos in Lang's book that was compiled by a student in Math 250A at the end of the Fall, 1992 semester. It is quite possible that many of these have been corrected in recent printings of the book; when I taught this course in 1992, the third edition of "Algebra" had just come out. =========================================================================== General comment: I prefer the "underbar" on the set inclusion symbol when the intention is that one set contains *or is equal to* another set. (Note: To compute line numbers, I have counted a diagram as one line.) p. 6, line -21: replace "H or G" by "H of G" p. 17, line 2: replace "G/K into G/H" by "G/K onto G/H" p. 19, line 14: replace "dagonal" by "diagonal" p. 19, line 24: what is "g" in "r >= g"? p. 26, line 4: replace "x(yx)" by "x(ys)" p. 26, line 5: replace "es = e" by "es = s" p. 26, line 13: replace "yxy^-1" by "xyx^-1" p. 27, line -12: replace "normalizer" by "centralizer" (I'm not sure about this one) p. 29, line 14: replace "G = \prod Gs_i" by "S = \coprod Gs_i" p. 29, line -8: replace "we called" by "we call" p. 30, line -3: replace "\pi(\tau)f(x_{\sigma(1)}, \dots , x_{\sigma(n)})" by "\pi(\sigma)f(x_{\tau(1)}, \dots , x_{\tau(n)})" p. 34, line 15: replace "that G has a" by "G has a" p. 36, line 10: replace "is H be assumption" by "is H by assumption" p. 36, line 15: replace "p, q be the distinct" by "p, q be distinct" p. 36, line 15: replace "distinct porimes" by "distinct primes" p. 37, line -11: What does "0" mean? Should it be the set "{0}"? This occurs in many subsequent places. p. 39, line -14: replace "by the element of T" by "by the elements of T" p. 42, line -14: replace "The A(p) is" by "Then A(p) is" p. 42, lines -2, -3, -4: exchange "p" and "q" everywhere p. 42, line -3: replace "= 1," by "= 0," p. 53, line -17: replace "Mor(B,C) x Mor(A, B)" by "Mor(A, B) x Mor(B, C)" p. 53, line -12: exchange "left" and "right" p. 56, line -15 (middle diagram): replace "A'" in lower left corner by "A" p. 56, line -14: replace "A" by "\cal A" p. 56, line -7 (lower diagram): what is "[h]"? What are the brackets for? p. 60, line 17: replace "x' on x" by "x' to x" p. 61, line -7: replace "Exercises 50-58" by "Exercises 50-56" p. 62, line 3 (top diagram): this diagram has many mistakes p. 62, line 14: replace "their coproduct is" by "their product is" p. 63, line 11: replace "gorups" by "groups" p. 68, line 10 (top diagram): replace "\lambda_*" by "(f_{s'} \circ \lambda)_*" p. 72, line 14: I think the statement of this proposition is flawed. p. 75, lines -12 and -16: I find this notation difficult. What are the unions ranging over? p. 76, line 14: replace "(x_1 x_2 ^{\psi(h_1)}" by "(x_1 x_2 ^{\psi(h_1)(x_2)}" p. 77, line 15: replace "finite grop" by "finite group" p. 81, line -13 (exercise 54): The G_i should generate G p. 88, line -2: replace "as additive" by "as an additive" p. 93, line -7: regarding "every ideal is principal", what about n=0? p. 96, line -11: replace "the endomorphisms" by "the endomorphism" p. 108, line -1: replace "\phi(a) = a/1" by "\phi_s(a) = a/1" p. 118, line -8: replace "that A_{tor} is" by "that M_{tor} is" p. 120, line 3: replace "section 4" by "section 3" p. 124, line -3: replace "space over K," by "space over K." p. 128, line 19: replace "Proposition 9.1" by "Proposition 7.1" p. 136, line 12: replace "as A-module" by "as A-modules" p. 137, line 7: replace "Chapter I, section 9" by "Chapter I, section 7" p. 147, line 7: replace "M = M_r" by "M_{r+1} = M_r" p. 153, line 15: replace "for M as linear" by "for M as a linear" p. 158, line -13: replace "Let z \in Ker d''" by "Let z'' \in Ker d''" p. 162, line 16: replace "complete disctete" by "complete discrete" p. 168, line 2-4 (exercise 10a): missing subscript "p" in 5 places p. 229, line -11: replace "\alpha_0 + \alpha_1" by "a_0 + a_1" p. 232, line 17: replace "Let E" by "Let L" (I'm not sure about this one) p. 239, line 12 (diagram): top arrow should point from L to L' p. 241, line 12: replace "By Theorem 4.1" by "By Corollary 4.2" p. 241, line -6: replace "a_i_n)" by "\alpha_i_n)" p. 254, line 2: What is "K"?