Errata for Good Math

We try to keep our books accurate, but sometimes mistakes creep in. This page lists the errors submitted by our astute readers. If you've found a new error, please submit it.

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PDF	Description	Found in
5	#51448: For consistency in description of Equality rules, use either "=", or "is equal to" exclusively. The switch happens abruptly mid-sentence. "...more...	B5.0 05-May-13
15	#51449: Remove some duplication from chapter introduction. "But the next step in understanding numbers is looking at numbers that have non-integer ...more...	B5.0 05-May-13
39	#51168: "Why is a bizzare irrational number": should be spelled "bizarre"--Tom Verhoeff	B5.0 01-Apr-13
105	#51463: Figure 11 is misnumbered. Steps 14-17 should be 13-16 to match the proof.--Ian Price	B5.0 07-May-13
112	#51465: Definition of parent relation not given in listing, but text refers to it. "First, we have two lines that define what a parent is in terms of logic."--Ian Price	B5.0 07-May-13
113	#51466: cousin relation is duplicated across two listings.--Ian Price	B5.0 07-May-13
120	#51467: Comment for partition relation is wrong. It should read "B = C + [A] + D" since A is the pivot, and B is the original list. That said, it m...more...	B5.0 07-May-13
136	#51469: Can you provide an explanation of the use of ≨ in the set theory definitions? I expected an '=' or 'if' or 'iff', and this "less than but not ...more...	B5.0 07-May-13
153	#51480: "The easiest variation of the axiom of choice is called the well-ordering theorem." This line feels a little weird, since it is like you are i...more...	B5.0 08-May-13
160	#51479: "indunction rule" should be "induction rule"--Ian Price	B5.0 08-May-13
172	#51481: Table 3 is not symmetrical. Row j, Col b = 1(mistake). Row b, Col j = h. Row c, Col e = i. Row e, Col c = space(mistake). Row d, Col g = g. Ro...more...	B5.0 08-May-13
183	#51483: "we cake the blocks" -> "we take the blocks"--Ian Price	B5.0 08-May-13
225	#51208: 1st line of page 225: "Leibniz" is the correct name of Newtons co-inventor.--Dr. Frid Ruland	B5.0 03-Apr-13
232	#51209: That would reduce our expression to (λ x y z . + (* x x) y) 5 20 4. Next, we’d reduce the outermost λ: (+ (* 5 5) 30), which would evaluate ...more...	B5.0 03-Apr-13
236	#51061: "treated as if the expression were: “(λ square . square 4)(λ x . x×x)”.": the expression should be "(λ x . x*x) 4" (also note the asterisk ins...more...	B4.0 15-Mar-13
239	#51068: "You write functions that combine other functions in order to make it do what you want.": Does not sound right grammatically, because "it" is ...more...	B4.0 15-Mar-13
240	#51210: • And = λ x y . x y FALSE --> • BoolAnd = λ x y . x y FALSE--Dr. Frid Ruland	B5.0 03-Apr-13
240	#51211: • BoolNot = λ x . x FALSE TRUE* Question on my part: what is TRUE* Typo or special convention?--Dr. Frid Ruland	B5.0 03-Apr-13
242	#51212: In fact, we can say in general that for any NN! = N * (N-1)!. --> In fact, we can say in general that for any N! = N * (N-1)!.--Dr. Frid Ruland	B5.0 03-Apr-13
245	#51078: Figure 18: the two "λ y" nodes on the middle level need to be "λ x".--Tom Verhoeff	B4.0 15-Mar-13
250	#51213: last line: a function type α→ δis a logical implication: passing --> a function type α→ δ is a logical implication: passing--Dr. Frid Ruland	B5.0 03-Apr-13
250	#51169: "a function type α → δis": insert a space before "is"--Tom Verhoeff	B5.0 01-Apr-13
250	#51170: "a function type α → δis a logical implication: passing a value of type α to the function implies that the return type will be β.": The "β" sh...more...	B5.0 01-Apr-13
251	#51528: "but since we know that “+” is a function with type “α → α”, we can infer that the result type of this function will be “α”" Should probabl...more...	B5.0 16-May-13
251	#51171: "First, we need modify": insert "to" after "need"--Tom Verhoeff	B5.0 01-Apr-13
251	#51172: "first parameter is type α": either change "is" into "has", or insert "of" before "type"--Tom Verhoeff	B5.0 01-Apr-13
251	#51173: "shorthand for currying. is just ...": Something is missing before "is just"--Tom Verhoeff	B5.0 01-Apr-13
252	#51214: p. 252 and 253 the examples for the simplified version of type inference rules for Type Invariance Function Type Inference Functi...more...	B5.0 03-Apr-13
252	#51174: Explain the notation involving "⊧" before using it in examples; also the use of + with contexts.--Tom Verhoeff	B5.0 01-Apr-13
253	#51529: "* is a function from a number to a number, so since we’re using x as a parameter to " again, is a binary operator. This should either b...more...	B5.0 16-May-13
253	#51175: "Example:λ x y ...": insert space after ":"--Tom Verhoeff	B5.0 01-Apr-13
254	#51530: "Since we don’t know what type it returns, we’ll use another new type variable u, and say y: u (function type inference). By doing function ap...more...	B5.0 16-May-13
254	#51176: "(λ x:t y: t → u. (y x): u) t → (t → u) → u": a colon is missing after "u)"--Tom Verhoeff	B5.0 01-Apr-13
255	#51177: "Let’s take another look at the types the simply typed lambda calculus.": insert "in" after "types" (or fix the grammar in some other way).--Tom Verhoeff	B5.0 01-Apr-13
255	#51178: "the following grammar ...": the given grammar does not make sense.--Tom Verhoeff	B5.0 01-Apr-13
257	#51179: "a typed LC": this seems to be the only place where the abbreviation "LC" (for Lambda Calculus" is used; write out in full.--Tom Verhoeff	B5.0 01-Apr-13
263	#51532: "And, finally, the way that we would write that a program p doesn’t halt for input i as C(p, i) = _." Underscore should be ⊥. --Ian Price	B5.0 16-May-13
264	#51533: "Or less formally, can I write a progrm which tells" progrm -> program--Ian Price	B5.0 16-May-13
264	#51534: "C(pair(p, i)) = _." <- should be bottom--Ian Price	B5.0 16-May-13
264	#51535: Oracle definition uses Phi, but elsewhere you use O.--Ian Price	B5.0 16-May-13