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Subject: |
[Typo] in Calc-Manual: Rewrite Rules - exercise 1 |
Date: |
Tue, 4 Apr 2023 03:12:22 +0900 |
In Calc's Manual 2.5.2: Section: Rewrite Rules,
https://www.gnu.org/software/emacs/manual/html_mono/calc.html#Rewrites-Tutorial
There is the following typo.
In the Exercise-1 shows following:
```
1: [merge, secsqr] 1: [a/x + b/x := (a + b)/x, ... ]
. .
' [merge,sinsqr] RET =
```
You can see, it says that when entering [merge, sinsqr] it becomes
[merge, secsqr].
I believe the `sinsqr` was supposed to be `secsqr`.
(In fact there is no mention of `sinsqr` in the whole manual).
Garid.
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--- Begin Message ---
Subject: |
Re: bug#62658: [Typo] in Calc-Manual: Rewrite Rules - exercise 1 |
Date: |
Sat, 08 Apr 2023 19:15:20 +0300 |
> From: Garid Zorigoo <garidzorigoo@gmail.com>
> Date: Fri, 7 Apr 2023 21:46:21 +0900
> Cc: 62658@debbugs.gnu.org
>
> > It's possible. But I tried to run the example, and I seem to be
> > unable to get past the formula I'm asked to enter after the "m s"
> > part: I get error messages.
>
> Sorry, which "m s" are you referring to?
> The section I referred to (from the start of "3.5.2 Rewrite Rules" to
> first 2 entries of "Exercise 1") didn't have the command "m s".
>
> > Could you perhaps show the commands and keys to type
>
> To reproduce it'll need the following commands (in emacs -Q).
> (These are copied from Rewrite-Rules 3.5.2 (in emacs-28)
> or 2.5.2 (website). I picked up only entries /omitted outputs/)
>
>
> ' 2sec(x)^2/tan(x)^2 - 2/tan(x)^2 <RET> s 1
> a r a/x + b/x := (a+b)/x <RET>
> a r sec(x)^2 := 1 + tan(x)^2 <RET>
>
>
> ' a/x + b/x := (a+b)/x <RET> s t merge <RET>
> ' sec(x)^2 := 1 + tan(x)^2 <RET> s t secsqr <RET>
> r 1 a r merge <RET> a r secsqr <RET>
>
>
> ' [merge,sinsqr] <RET> =
> s t trig <RET> r 1 a r trig <RET>
>
>
> According to the manual, the output after the last line should be 2.
>
> I wrote the following tables, slightly detailed manner.
> The First column represents what you enter, the 2nd column represents what
> the result is.
>
> Part I: (Not required for re-creating error)
> | command | result |
> |---------------------------------------+-----------------------------|
> | '2sec(x)^2/tan(x)^2 - 2/tan(x)^2<RET> | 2sec(x)^2/ ... |
> | s 1 | same |
> | a r a/x + b/x := (a+b)/x <RET> | (2 sec(x)^2 - 2) / tan(x)^2 |
> | a r sec(x)^2 := 1 + tan(x)^2 <RET> | 2 |
>
> Part II: (required for re-creating error, because saving expressions)
> | command | result |
> |----------------------------------+-----------------------------|
> | ' a/x + b/x := (a+b)/x <RET> | a/x + b/x := (a+b)/x |
> | s t merge <RET> | disappear |
> | ' sec(x)^2 := 1 + tan(x)^2 <RET> | sec(x)^2 := 1 + tan(x)^2 |
> | s t secsqr <RET> | disappear |
> | r 1 | 2sec(x)^2/... |
> | a r merge <RET> | (2 sec(x)^2 - 2) / tan(x)^2 |
> | a r secsqr <RET> | 2 |
>
>
> Exercise I:
> | command | result |
> |------------------------+------------------------------------------|
> | ' [merge,sinsqr] <RET> | [merge,sinsqr] |
> | = | [a / x + b / x := (a + b) / x, sinsqr] |
> | | above, you can see sinsqr didn't expands |
> | | |
> | s t trig <RET> | disappear |
> | r 1 | 2 sec(x)^2 / tan(x)^2 - 2 / tan(x)^2 |
> | a r trig <RET> | 2 sec(x)^2 / tan(x)^2 - 2 / tan(x)^2 |
> | | above, you can see it didn't change. |
> | | It should've outputted 2 |
>
>
> Here is what I think it should be:
> Exercise I (My suggestion):
> | command | result |
> |------------------------+--------------------------------------------|
> | ' [merge,secsqr] <RET> | [merge,secsqr] |
> | = | [a / x + b / x := (a + b) / x, sec(x)^2... |
> | | above, you WILL see SECSQR expands |
> | | |
> | s t trig <RET> | disappear |
> | r 1 | 2 sec(x)^2 / tan(x)^2 - 2 / tan(x)^2 |
> | a r trig <RET> | 2 |
> | | above, you WILL see 2 |
>
>
> (Just in case, it might being helpful, I also attached the
> asciicinema recording in the email)
Thanks, I've now made the fix, and I'm closing this bug.
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