PLP Errata

As of October 2003 Programming Language Pragmatics is in the fifth printing of its first edition. To tell which printing you have, check the copyright page. Three lines below the copyright symbol there is a line of numbers. If the last number is a 1 you have the first printing. If the last number is a 2 you have the second printing. If the last number is a 3 you have the third printing, etc.

First through fifth printings

page xxi, Acknowledgments: add Andrew Tolmach to the list of reviewers.
page 42, figure 2.5, left-pointing arc near top of figure, currently labeled "non-)": relabel "non- ) or *".
page 55, first line of first full paragraph: replace "Figure 2.12" with "Figure 2.11".
page 56, figure 2.12: node labeled "+" should be replaced by "add_op", with a "+" child; node labeled "/" should be replaced by "mult_op", with a "/" child.
page 64, second line of text: replace "FOLLOW(β)" with "FOLLOW(A)".
page 132, third line after first displayed code fragment: replace "a another" with "another".
page 136, figure 3.14: 6th long box (for P1), replace "(1)" with "(2)".
page 150, second displayed code fragment: replace "inner" with "B". Make the same change in the first line of the immediately following paragraph.
page 178, figure 4.8: in part (b), replace "1" in the box at the bottom with "3".
page 188, figure 4.12: in the two lines immediately before the six elided lines, replace "F_?" with "F₄".
page 250, line 11: replace "examing" with "examining".
page 251, second-to-last line of last full paragraph: replace "deferencing" with "dereferencing".
page 253, figure 6.1, row 6 of table: add "<," to Ada column; add "<, <=, >, >=, =, <>, IN" to Pascal column.
page 288, figure 6.5, lines 6 and 11: replace "i +:= by" with "i := i + by"; lines 5 and 10: replace "yield i" with "yield(i)"; last line of top (partial) paragraph: replace "last - first" with "(last - first)".
page 289, figure 6.6, lines 6 and 12: parenthesize argument to yield; line 9: replace "from_to" with "int$from_to"; line 12: replace "{l, r}" with "{left: l, right: r}".
page 334, line 6: replace "5" with "4".
page 347, bottom of page: replace the two definitions of square, and the intervening text, with:
fun square(x) = x * x;

Here the compiler cannot tell whether * is meant to refer to integer or floating-point multiplication; it assumes the former by default. If this is not what the programmer wants, the alternative must be specified explicitly:

fun square(x : real) = x * x;
page 374, second line of footnote: replace "orginally" with "originally".
page 376, first line of second paragraph: replace "five" with "three", and "10" with "six".
page 381, last three lines (displayed code): replace "C :=" with "A :=" (three times).
page 389, second-to-last line on page: replace "a" with "b".
page 410, second-to-last line of last displayed code fragment: replace ");" with ", r[i]);".
page 411, just below third displayed code fragment: replace "&s" with "%s".
page 472, 7th line up from the bottom: replace "subroutines" with "variables".
page 553, displayed code fragment: replace "delete" with "delete[]".
page 585: exercises 10.13 and 10.14 should be starred.
page 598, line 10: replace "later" with "latter".
page 637: (1) in first displayed code fragment, replace ">" with ">=".
(2) in paragraph immediately before "Database Manipulation" heading, replace "greater than 32" with "at least 32".
(3) in display near bottom of page: right hand side should be
```
      ','(rainy(rochester),
          ','(rainy(seattle),
              ','(cold(rochester),
                  :-(snowy(X), (rainy(X),
                             cold(X))))))
      
```
page 759, caption of Figure 13.11: replace "v25 and v21" with "v25, v31, and v33".
page 766, 4th line up from the bottom: replace "-1th" with "zero-th".
page 782, exercise 13.5: in both blocks of displayed code, replace "index" with "i" (one occurrence in each block).
page 796, last line: replace "C" with "C++".

First through fourth printings only

page 56, figure 2.12, leftmost subtree: replace "id(B)" with "id(A)".
page 67, figure 2.16: insert "+, -," at the beginning of the PREDICT set for factor_tail → ε.
page 225, figure 5.8: insert a new line of code before the current final line, reading "r2 := r2 – 1".
page 281, displayed code fragment: move label "10:" to second line of code (the elipses).
page 309, second line of last full paragraph: replace second occurrence of "in" with "to".
page 630, figure 11.4: add period at end of fourth Prolog clause.
page 633, second displayed code fragment: replace "good(A) :- block_split(A)." and "good(A) :- build(A)." with "good(A) :- strong_build(A)." and "good(A) :- weak_build(A)." Then on p. 634, replace five lines starting with "Our fourth choice" with
Our fourth choice is to build toward three in a row (i.e., to get two in a row) in such a way that the obvious blocking move won't allow our opponent to build toward three in a row:
```
strong_build(A) :- x(B), line(A, B, C), empty(C), not(risky(C)).
risky(C) :- o(D), line(C, D, E), empty(E).
```
Barring that, our fifth choice is to build toward three in a row in such a way that the obvious blocking move won't give our opponent a split:
```
weak_build(A) :- x(B), line(A, B, C), empty(C), not(double_risky(C)).
double_risky(C) :- o(D), o(E), different(D, E), line(C, D, F),
    line(C, E, G), empty(F), empty(G).
```
Make the same code changes on p. 639, figure 11.7. Finally, in that same figure, delete the second done rule and replace the play rule with
```
play :- not(clear), repeat, getmove, respond.
respond :- ordered_line(A,B,C), o(A), o(B), o(C), printboard, write('You won.'), nl.
           % shouldn't ever happen!
respond :- makemove, printboard, done.
```
page 749, figure 13.6, second line of code in Block 2: replace upper-case "V" with lower case "v".

First, second, and third printings only

page 172, figure 4.3, production 3: replace second "TT₁" with "TT₂".
page 345, third full paragraph, first line: replace "complied" with "compiled".
page 408, first displayed code fragment: replace "character(20) s" with "character s*20"; replace "real(10) r" with "real r(10)"; add comma after last closing parenthesis in write statement.
Second and third displayed code fragments: add comma after closing parenthesis in write statement.
Fourth displayed code fragment: add comma after "print*".
Fifth displayed code fragment: add comma after "100"; add comma after "read*".
page 475, last line of displayed code: replace "resume" with "transfer".
page 612, second-to-last sentence: replace with "Mathematically, a function is a single-valued mapping: it associates every element in one set (the domain) with (at most) one element in another set (the range)."
page 613, second-to-last line: replace "injective" with "single-valued".
page 695, footnote: replace "vrygeren" with "vrijgeven".
Appendix A. Some of the URLs have gone stale. More up-to-date versions can be found in the on-line version of the appendix. Please report additional stale links to .

First and second printing only

page 27, exercise 1.4: replace "Show that the two programs compute the same result." with "Does this program compute the same result? If not, can you fix it?"
page 66, first set subroutine for strings, 5th line: delete "(yet)".
page 92, second block of displayed equations: surround second line with an extra set of parentheses; surround fourth line with another.
page 251, last displayed code fragment: replace ":=" with "=".
page 478, 6th line up from the bottom: replace "in the previous section" with "on p. 475".
page 848 (index). Add missing apostrophe in "Pascal's triangle".

First printing only

page 31, line 4: replace "langauge" with "language".
page 49, third full paragraph, line 7: replace ", id_list" with ", id id_list_tail".
page 52, grammar fragment in lower left: delete "id" in first production.
page 101, problem 2.18: replace "parser for" with "parser for the string A, B, C;, using" (with "A, B, C;" in typewriter font).
page 136, figure 3.14: In each of the 7th, 8th, and 9th horizontal boxes, which form a cascading chain around the middle of the page, replace the "1" (one) in the second sub-box (Name field) with an "I" (capital i).
page 189, figure 4.13: child of right-most "TT" node is missing; should be labeled with an epsilon.
page 223, figure 5.7: replace "Integer address registers" with "Integer general registers" in the MIPS IV portion of the figure.
page 241, second full paragraph, 10th line: replace "all of this state must be saved to memory" with "it must save all this state to memory, or arrange for the processor to trap back into the OS if the new process attempts to access an unsaved window." (The Sparc allows individual windows to be tagged as valid [accessible] or invalid [inaccessible]. Any attempt to move to an invalid window, or to change valid/invalid designations, results in a trap.)
page 300, text line after first displayed code fragment: replace "O(n²)" with "exponential".
page 301, definition of DIVIDES: replace "a,n" with "n,a".
page 338, first displayed code fragment: add semicolon at end of line 4.
page 398, first paragraph, line 5: replace "usless" with "useless".
page 416, line 3: replace "refer" with "refer to".
page 510, 3rd-to-last line of text: replace "liked" with "linked".
page 520, figure 9.11, last line of code in column 2: replace "*to" with "*t0".
page 525, exercise 9.4: move closing parenthesis to after "[Har92]".
page 607, second code display, 4th line: replace "stream" with "s".
page 613, first full paragraph, line 8: cut comma.
page 632, figure 11.5: in the right-hand node in the second level of the tree, replace "edge" with "path".
page 642, 7th line up from the bottom: replace "further" with "further later in this section".
page 654, exercise 11.19, 3rd-to-last line: replace "so" with "show".
page 692, displayed code: replace "acquire" with "acquire_lock" and "release" with "release_lock". Make same change (twice for each name) in figure 12.12 (page 693) and again (twice for each name) in figure 12.14 (page 696).
page 699, figure 12.16: swap "–:=" and "+:=".

Thanks to the following for help in catching these mistakes: Anthony Adachi, Manuel E. Bermudez, John Boyland, Brian Cumming, Stephen A. Edward, Michael J. Eulenstein, Andrey Garbanzo, Eileen Head, Paul Ilardi, Lucian Ilie, Eric Joanis, Les Lander, Hui Li, Jingke Li, Esteban Meneses, Eduardo Pinheiro, Zongyan Qiu, Nick Stuifbergen, Ray Toal, Andrew Tolmach, Jens Troeger, Robbert vanRenesse.

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Last Change: 30 October 2005 / Michael Scott's email address