@Kitonum 

Thank you very much for your reply and instruction to me.

Best wishes.

taro

@Carl Love 

Thank you for your teaching.

taro

@Carl Love 

Thank you, Carl Love,

I didn't know the form of `+`(a,b), before, though I wondered whether there weren't forms in Maple, similar to 

 Plus[a,b], which means a+b in Mathematica.

Thank you for telling me about that.

Best wishes.

Taro Yamada

@Carl Love 

Thank you.

I could understand your explanation.

I could understand that It used skillfully the way a expression with neutral operator is expressed in two ways:

a &* b and &*(a, b).

Taro Yamada

@acer 

I'm sorry for being late for writing this reply.

Thank you for your teaching. I can't understand the content of your program yet.

But, I will try to understand it. Though I think I might need your further instruction about it,

in that time please take care of me.

Best wishes.

taro yamada 

@acer 

Thank you.

I hadn't known that good way of modifying equations until you taught it to me.

I owe you a lot.

@acer 

In my case of snowleopard,

there were maple 9 command line version and that of maple 17, in

maple9
/Applications/Maple\ 9.app/Contents/MacOS/bin/maple

maple17
/Library/Frameworks/Maple.framework/Versions/17/bin/maple

,respectively.

Thank you for teaching me about there being a command-line version.

taro

@acer 

I could get the same result as yours with command line maple9.

Thank you.

Taro.

@Carl Love

@acer 

Thank you for your comments, and thank you for telling me the command kernelopts(version).

> kernelopts(version);
Maple 9.01, APPLE PPC OSX, Jul 9 2003 Build ID 137227

I copied and paseted the code which acer ascertained: 

shift:=(f::procedure)->(x->(f(x+1))):

shift(sin);

Then, my result was

x -> f(x + 1)

%(Pi/6-1);

1
-
2

And, @Carl Love

As for the guide, there is no on-line manual in the Help probably, which situation is different from

that of Maple 17, which does not have a book edition of programming guides.

(As I haven't tried to use a guide from Help menue, I might be wrong as for whether Advanced Programming

Guide is available from the Helpmenue. But, as long as I checked it now, I couldn't find it from it. )

I don't know why this inconvenience that the prescription of the Shift Operator cannot be recreated is occuring to me.

taro 

@Carl Love 

I can't understand how having the property of being right-associative is helpful.

But, thank you for teaching me that it does not need parentheses.

taro

By the way, the code of A Shif Operator was from Maple9's advanced programming guide, p 17.

I cannot understand why this sort of thing happen though it does not have any typos at least for intoroductory programming guide. I have an impression that maple's books are completely proofread.

@Preben Alsholm 

Thank you for your instruction.

I checked it with Maple 17 after I read your reply, then I could obtain the result as I wanted to obtain.

As you pointed out, I first wrote it with Maple9. Though I had intended to check it with Maple 17 and did it, then 
i couldn't obtain the right answer, but now I could obtain the right answer. I'm sorry.

Taro

@Carl Love 

Thank you for your instruction to this question as well as to another question of 

http://www.mapleprimes.com/questions/201707-About-Quicksort

I wote a reply of mine in the above page.

Thank you very much.

taro

@Carl Love

Thank you for your teaching me a lot.

Without your very kind instruction, I couldn't understand what maple showed as the result of quicksort.

That program is on Advanced Programming Guide of Maple 9, page 10. And, I asked about it, as I thought it is important to know about how maple invocates a program with nested procedures. In the Introductory Programming Guide,

I thought that there was no description of layers of invocated level, which I expressed as this as I can't see how I should express this. At least, there was no explicit explanation about it in it. Seeing "top level" in the book, I couldn't understand it because I didn't know layers.

And, thank you for telling me about "infolevel." This is surely very helpful tool. I will absolutely use it from now.

And, thank you for showing me a model of indentation of a code. Identation is explained in introductory programming gude, p225, and the original code of quicksort had an indentation. But, watching your indentation of the code will be definitly helpful to me as a model in writing a code.

First, I thought I would delete this first post of my question about quicksort, to find no reply from others for a while , and actually deleted this question. But, then, I noticed your above reply to this question, after I read your reply to another related question of me about nested procedure of quicksort. The present question was not actually deleted very luckily to me.

Thank you very much for a lot of your instruction to me.

Taro

@Preben Alsholm 

I could understand the use of array well.

thank you.

@SandraShklyaeva 

I could show the graph with MAPLE WWW, when I use Google Chrome.

But, on the other hand, I couldn't open the same file with Safari Version 5.1.10.

This might be from the Sarafi I am using being old.

Anyway, your MAPLE WWW run well. Thank you.

taro