[Emacs-diffs] Changes to emacs/man/calc.texi

[Jay Belanger]

Index: emacs/man/calc.texi
diff -c emacs/man/calc.texi:1.34 emacs/man/calc.texi:1.35
*** emacs/man/calc.texi:1.34    Sun Jan  2 05:01:08 2005
--- emacs/man/calc.texi Tue Jan  4 14:46:41 2005
***************
*** 5859,5873 ****
  so that @expr{2 - 3 (x + y) + x y} is a sum of three terms.)
  @xref{Rewrites Answer 5, 5}. (@bullet{})
  
! (@bullet{}) @strong{Exercise 6.}  Calc considers the form @expr{0^0}
! to be ``indeterminate,'' and leaves it unevaluated (assuming Infinite
! mode is not enabled).  Some people prefer to define @expr{0^0 = 1},
! so that the identity @expr{x^0 = 1} can safely be used for all @expr{x}.
! Find a way to make Calc follow this convention.  What happens if you
! now type @kbd{m i} to turn on Infinite mode?
! @xref{Rewrites Answer 6, 6}. (@bullet{})
! 
! (@bullet{}) @strong{Exercise 7.}  A Taylor series for a function is an
  infinite series that exactly equals the value of that function at
  values of @expr{x} near zero.
  
--- 5859,5865 ----
  so that @expr{2 - 3 (x + y) + x y} is a sum of three terms.)
  @xref{Rewrites Answer 5, 5}. (@bullet{})
  
! (@bullet{}) @strong{Exercise 6.}  A Taylor series for a function is an
  infinite series that exactly equals the value of that function at
  values of @expr{x} near zero.
  
***************
*** 5913,5921 ****
  rearranged or if @kbd{a s} needs to be typed after rewriting.  (This one
  is rather tricky; the solution at the end of this chapter uses 6 rewrite
  rules.  Hint:  The @samp{constant(x)} condition tests whether @samp{x} is
! a number.)  @xref{Rewrites Answer 7, 7}. (@bullet{})
  
- @c [fix-ref Rewrite Rules]
  @xref{Rewrite Rules}, for the whole story on rewrite rules.
  
  @node Programming Tutorial, Answers to Exercises, Algebra Tutorial, Tutorial
--- 5905,5916 ----
  rearranged or if @kbd{a s} needs to be typed after rewriting.  (This one
  is rather tricky; the solution at the end of this chapter uses 6 rewrite
  rules.  Hint:  The @samp{constant(x)} condition tests whether @samp{x} is
! a number.)  @xref{Rewrites Answer 6, 6}. (@bullet{})
! 
! Just for kicks, try adding the rule @code{2+3 := 6} to @code{EvalRules}.
! What happens?  (Be sure to remove this rule afterward, or you might get
! a nasty surprise when you use Calc to balance your checkbook!)
  
  @xref{Rewrite Rules}, for the whole story on rewrite rules.
  
  @node Programming Tutorial, Answers to Exercises, Algebra Tutorial, Tutorial
***************
*** 6643,6650 ****
  * Rewrites Answer 3::      Rewriting opt(a) + opt(b) x
  * Rewrites Answer 4::      Sequence of integers
  * Rewrites Answer 5::      Number of terms in sum
! * Rewrites Answer 6::      Defining 0^0 = 1
! * Rewrites Answer 7::      Truncated Taylor series
  * Programming Answer 1::   Fresnel's C(x)
  * Programming Answer 2::   Negate third stack element
  * Programming Answer 3::   Compute sin(x) / x, etc.
--- 6638,6644 ----
  * Rewrites Answer 3::      Rewriting opt(a) + opt(b) x
  * Rewrites Answer 4::      Sequence of integers
  * Rewrites Answer 5::      Number of terms in sum
! * Rewrites Answer 6::      Truncated Taylor series
  * Programming Answer 1::   Fresnel's C(x)
  * Programming Answer 2::   Negate third stack element
  * Programming Answer 3::   Compute sin(x) / x, etc.
***************
*** 9094,9141 ****
  match before later rules; @samp{nterms(x)} will only be tried if we
  already know that @samp{x} is not a sum.
  
! @node Rewrites Answer 6, Rewrites Answer 7, Rewrites Answer 5, Answers to 
Exercises
  @subsection Rewrites Tutorial Exercise 6
  
- Just put the rule @samp{0^0 := 1} into @code{EvalRules}.  For example,
- before making this definition we have:
- 
- @smallexample
- @group
- 2:  [-2, -1, 0, 1, 2]                1:  [1, 1, 0^0, 1, 1]
- 1:  0                                    .
-     .
- 
-     v x 5 @key{RET}  3 -  0                    V M ^
- @end group
- @end smallexample
- 
- @noindent
- But then:
- 
- @smallexample
- @group
- 2:  [-2, -1, 0, 1, 2]                1:  [1, 1, 1, 1, 1]
- 1:  0                                    .
-     .
- 
-     U  ' 0^0:=1 @key{RET} s t EvalRules @key{RET}    V M ^
- @end group
- @end smallexample
- 
- Perhaps more surprisingly, this rule still works with Infinite mode
- turned on.  Calc tries @code{EvalRules} before any built-in rules for
- a function.  This allows you to override the default behavior of any
- Calc feature:  Even though Calc now wants to evaluate @expr{0^0} to
- @code{nan}, your rule gets there first and evaluates it to 1 instead.
- 
- Just for kicks, try adding the rule @code{2+3 := 6} to @code{EvalRules}.
- What happens?  (Be sure to remove this rule afterward, or you might get
- a nasty surprise when you use Calc to balance your checkbook!)
- 
- @node Rewrites Answer 7, Programming Answer 1, Rewrites Answer 6, Answers to 
Exercises
- @subsection Rewrites Tutorial Exercise 7
- 
  @noindent
  Here is a rule set that will do the job:
  
--- 9088,9096 ----
  match before later rules; @samp{nterms(x)} will only be tried if we
  already know that @samp{x} is not a sum.
  
! @node Rewrites Answer 6, Programming Answer 1, Rewrites Answer 5, Answers to 
Exercises
  @subsection Rewrites Tutorial Exercise 6
  
  @noindent
  Here is a rule set that will do the job:
  
***************
*** 9208,9214 ****
  this it would probably be better to write the formatting routine
  in Lisp.)
  
! @node Programming Answer 1, Programming Answer 2, Rewrites Answer 7, Answers 
to Exercises
  @subsection Programming Tutorial Exercise 1
  
  @noindent
--- 9163,9169 ----
  this it would probably be better to write the formatting routine
  in Lisp.)
  
! @node Programming Answer 1, Programming Answer 2, Rewrites Answer 6, Answers 
to Exercises
  @subsection Programming Tutorial Exercise 1
  
  @noindent