*4/12/96
                  ERRATA FOR THE 3RD PRINTING (June, 1995)

               Programming Languages Principles and Practice

                          by Kenneth C. Louden


Page 82, Figure 4-6b:
     In the syntax diagram for a program-module, there should be
     a path around module-priority, from the rectangle labeled
     "identifier" to the circle labeled with a semicolon.

Page 146, Exercise 10, line 3:
     "blocks of function p, procedure q, and the main program"
     should appear as
     "blocks of function p, procedure print, and procedure q"

Page 270, paragraph 1:
     "w := z + z"
     should appear as
     "w := z + z;"

Page 270, middle of page:
     "w := ComplexNumbers"+"(z,z);"
     should appear as
     "w := ComplexNumbers."+"(z,z);"

Page 293, Exercise 11, last line:
     "8.8" should appear as "8.1"

Page 323, code after 1st paragraph:
     "class rectangle
      { private:
        ..."
     should appear as
     "class rectangle
      { protected:
        ..."

Page 376, bottom of page:
     "(cond ((null? B) ())"
     should appear as
     "(cond ((null? B) '())"

Page 378, middle of page:
    "(if (null? L) ()"
    should appear as
    "(if (null? L) '()"

Page 396, last paragraph:
    "An example of a functional language with fully lazy evaluation is"
    should appear as
    "An example of a functional language with lazy evaluation is"

Page 419, Exercise 45(d):
    "Write out an implementation of your lambda expressions in (b) as"
    should appear as
    "Write out an implementation of your lambda expressions in (c) as"

Page 471, paragraph 1:
    Rule (18) should appear as:

                  <S|Env> => Env1
	     -------------------------
	     <S ';' L|Env> => <L|Env1>

Page 471, paragraph 1:
    Rule (19) should appear as:
      
	     L => <L|Env0>

Page 480, Figure 12-4 (continued):
    In the definition of the E semantic function, the
    following line was omitted and should be inserted above
    the last equation:
    "E[[I]](Env) = Env(I)"

Page 486, paragraph 3:
    "wp(S1;S2;Q) = wp(S1,wp(S2,Q))"
    should appear as
    "wp(L1;L2,Q) = wp(L1,wp(L2,Q))"
    Also, the reference to S1 and S2 later in the paragraph
    should be changed to L1 and L2.

Page 488, 1st paragraph:
    "H1(while B do L od, Q) = E>0 and wp(L,Q and E<=0)
     = E>0 and wp(S, H0(while E do L od, Q))"
    should appear as
    "H1(while E do L od, Q) = E>0 and wp(L,Q and E<=0)
     = E>0 and wp(L, H0(while E do L od, Q))"

Page 565, top of page:
    "(Some relaxation of the "same-length" requirement of Pascal are
    provided.)"
    should appear as
    "(Some relaxation of the "same-length" requirement of Pascal is
    provided.)"

Page 611, answer to 35:
    This is actually an answer to both Exercise 35 and Exercise 36.

Page 611, answer to 42:
    "A lambda expression for the twice functions is ..."
    should appear as
    "A lambda expression for the twice function is ..."

Page 617, first line:
    "P[[P]](a) = ..." should appear as "P[[L]](a) = ..."