Diary, February 1996

```                   1   2   3
4   5   6   7   8   9  10
11  12  13  14  15  16  17
18  19  20  21  22  23  24
25  26  27  28  29
```

Thursday, February 1, 1996

Oops, yesterday I thought it was the first of February. I quickly fixed it. Also received mail from Bert which he send from Japan. They arrived safely and had a warm welcome. They got a nice apartment. He will be working at the
Computational Sciences Division of the National Aerospace Laboratory.

Monday, February 5, 1996

(Especially for those outside Holland reading this:)

It is still snowing, although it is not so cold anymore. But what is more remarkable, is that the snow has remained for almost 10 days now.

I have been thinking about announcing this diary on the comp.infosystems.www.announce news group. (follow-up)

This is part of Fractal intuition by David Fowler.

My min_ruler.c program is using up all the otherwise wasted computer cycles of the glasshotel.cs.utwente.nl. Although, it runs on the lowest priority, it used about 92% of the CPU (and only 0.5% of the memory).

I found this in a posting by Peter Seebach in comp.lang.c:

```In article <4e4cu4\$95f@vixen.cso.uiuc.edu>, HOTARD  <jhotard> wrote:
>I am writing a program that looks at a character and then determines if it is a
>letter or number.  This program must use the switch command ...

main() {
int c, x, printf();
c = getchar();
switch (x = ((c = (unsigned char) c), /* try to ensure a legal char. */
((!!isdigit(c)) << 1) | ((!!isalpha(c)) << 0)))
default:
printf(
(x == 0 ? "'\\x%x' is neither a letter nor a number.\n" :
(x == 1 ? "'%c' is a letter.\n" : (x == 2 ? "'%c' is a number.\n" :
(x == 3 ? "'%c' is both a letter and a number.\n" :
"'\\x%x' is odd.\n"))), c);
return 0;
}
```

Tuesday, February 6, 1996

Mattijs de Vries offers his home build Quad 405/II VSE poweramp II for sale.

About Annabel

Today was the first time she did not cry/complain anymore when going into bath, since I freighted her. She even smiled a little.

(follow-up)

Wednesday, February 7, 1996

Sometimes, people in their enthusiasm can lurk into rather popularistic writing style in a serious scientific report, and say things like: `
Now read the rule again carefully' (red-lining by me). When I read this page in the report, it gave me the giggles.

[Added on February 8:]

But do not understand me wrong. I do respect the person who wrote this very much. His knowledge about the English language is far superior to mine. Not so long ago, he said to a student: `You are the first student, who wrote a flawless paragraph'. I got the impression that the student did not grasp the extend of this compliment. Up-to-today, I have not been able to follow the student's example. I also do not have the talent for writing, which this person has, because sometimes he produces a paragraph that would have taken me hours.

Embedded wierd C program

Kenneth A Reek wrote a posting to comp.lang.c:
In preparing some materials for a course, I wrote the following program to illustrate that the order of expression evaluation is not determined completely by the precedence of the operators involved. I ran it on every compiler I could find and, not surprisingly, got lots of different answers.

I'd like to get results from this program for as many different compilers as I can to drive home the point that expressions of this sort must be avoided. If you have access to a C compiler other than the ones listed below, I'd be grateful if you could run this program and send me the results. Please include the operating system you are using (if appropriate to the identification of the compiler) and the compiler version number if it has one.

Here's the program (hold on to your hats):

```	int main(){
int i = 10;

i = i-- - --i * ( i = -3 ) * i++ + ++i;
printf( "i = %d\n", i );
return 0;
}
```
Results found to date:
```21	Borland C/C++ 4.0, Turbo C++ 4.5
-86	Sun 3/50 cc
-85	Sun Sparc cc, SunOS 4.1.4 (a K&R compiler)
4	Sun Sparc acc, SunOS 4.1.4 (an ANSI compiler)
36	DEC VAX/VMS
21	Silicon Graphics Indy, IRIX 5.3
-63	gcc 2.6.3
```
I could add:
```-63     gcc version 2.4.5
```

Thursday, February 8, 1996

On
Monday, I wrote that I was thinking about announcing this diary on comp.infosystems.www.announce news group. The funny thing is that Bernie Wilt did announce his page with links to diaries on the net. Francisco van Jole must have read this announcement, and found my diary, because he mentions it in today's issue of Daily Planet, a Dutch mailing list with interesting pointers to things on the InterNet (in Dutch) provided by Planet Internet.

I wonder how many people are going to read my diary now. If you are reading this, please let me know what you think of it. So far, I have never got any email referring to my diary. Someway, I have always thought that only people from the other side of the world would read my diary pages, but now there might be many from inside Holland (I should say the Netherlands) that are going to read my pages.

Again this makes me ask myself the question (that I have asked myself many times before), why do I have this desire of writing my thoughts, ideas and experiences down, and even in a place where it could be read by complete strangers, or what might be worse, people who know me a little.

A pale winter sun

I just opened the blinds to enjoy the last bit of a nice winter sun going down. The blinds are outside, and can be controlled manually with two buttons on the inside. Although, you can let them go down and up by themselves automatically (determined by the amouth of light and wind), but it seems that nobody is using this functionality anymore. The reason is that the sensor for measuring the amouth of light is somewhere on the roof of the building. If there would be one in each room, it might have worked slightly better.

Friday, February 9, 1996

This morning I woke-up at 6 o'clock in the morning, realizing that it was lighter than usual in the room. I had left the curtains open yesterday evening. Our bedroom window looks out to some field, and the next houses are at least 100 meter (yard) away. Before I got married, I never closed the curtains, but
Li-Xia prefers it. The light I saw was from the street lights reflected on the clouds (fog).

At half past 7, I heard on the morning news that it was freezing 20 degrees Celsius outside. Li-Xia told me that we had three woolen caps, that I could use. I picked the one with Chicago Bulls (follow-up) on it, and used an extra shawl. But still my eyes were tearing when biked to the university.

I had to think about all those people living in Eastern Europe, who would consider -20 a warm winter day.

Monday, February 12, 1996

Online radio show by TROS radio

The story of Annabel crying in bath, was mentioned yesterday during the broadcast of the Online radio show, on the Dutch Radio 1 channel. Three days before she will turn 16 months (on Valentines Day) she made it on the national radio. That is a record in the history of our family! (See also last Thurday's entry for an explanation of how this came to happen.)

Because I did not record the broadcast, I emailed their customers service, and asked whether they could provide me a copy on tape. I was very happy, when I received an email from Yvonne van Bellen, to tell me that they send one for free! Thank you!

Serious newsgroups

This morning I saw a new new group with the name alt.magick.serious. I don't believe that the person(s) who created this news group have a good understanding of the USENET. The only way to get a serious news group is to pick a very boring topic of discussion, or create a news group with a name that does not say anything about its subject, and only reveal the name to restricted number of people. (But even that does not work in the long run.)

Hacking a document

Today, we had agreed to finish a document we have been working on for some time. At these kind of times, disaster is likely to strike. Only 15 minutes ago, Susan came in running in to tell me that the solution I had provided for an example did not work. When I looked at it, I had to agree that she was right. (So, was Justus, who had pointed out the problem at first in an email.) Studying it more, we came to the conclusion that we either had to remove the example, or modify the solution a lot (and still not being sure that it was correct). Then I suggested to modify the example slightly, by adding `i, ' at the proper place. Then we looked at the solution together, and it turned out, we only add to add `!i ', and nothing else. Which came as a surprise to both of us.

Valentines day, February 14, 1996

This seems to be a very important day. I printed out my Valentines card that I had made on
January 31, so I can give to Li-Xia, my girl-friend.

Yesterday evening, while doing the dishes, I heard some older man on the Radio refer to his `girl-friend'. Without thought, I assumed that he was not married, but probably living together with her. Then I realized that I always talk about Li-Xia as `my wife'. Suddenly, I realized it would be better to refer to her as my girl-friend, because she is my best female friend.

Wearable camera's

Steve Mann shows some of his private views:
(the latest he transmitted.)

Friday, February 16, 1996

One nice thing of an electronic diary is that you can rewrite it. I try to stick to the rule that I should not edit pages written on a previous day (except for the `next entries' links), but some times I take the freedom to modify something, because of the public nature of this diary, especially, when the things that I wrote are related to other people.
However, I feel completely free, to write the things on a page in any order I like. The remark about LOTOS below, was written before I wrote this.

The return of Guilds

It is funny to see, that with the existence of the InterNet guilds are returning. Some time ago, I already found the
International Programmers Guild. Today I found the HTML Writers Guild. And what to think of Declaration of Independence! by Elfi.

Computer Science: One of the most abstract sciences

I more I get into computer science, the more I get convinced that it is one of the most abstract sciences. If I talk about `computer science' in this context, I refer to the concept and methods that are used, not about computers or computer applications. The average user of computers (or the InterNet) do not have to know (and usually, do not know) anything about (theoretical) computer science, just like you do not have to be a linguist to be able to speak a language.

Currently, because computer science being a very young science, this is best seen in the confusion that is caused by terminology. If you are a computer scientist, tell me the meaning of the following words: process, task, object, interface, activity and method. (Probably, you can come up with 4 or 5 definitions for each word, especially if you think about other sub-fields of research.)

It would be funny to write a `Concise Computer Science Dictionary'.

About LOTOS

Please skip this section if you never heard of LOTOS.

We are using LOTOS in the TransCoop project, as one of our specification languages. LOTOS is an process algebraic language which is based on the concept of synchronization events between processes. Although this is a very powerful concept to model complex behaviour, it does have certain limits in the high-level specification of realistic systems. In such specification, one would like to use a gate (= a channel on which synchronization events take place) to represent the interface between a user and an application, where a single event indicates a operation to be performed, or a message being send. But this fails, because in case there is no synchronization, the reason remains unknown.

The idea that gates in LOTOS can be thought of communication channels between processes, is a misconception that is hard to avoid. From the design of distributed systems it is known that it is impossible to achieve synchronization with an finite number of messages being passed between the distributed components of the system.

How ever, LOTOS can be used to specify the low-level protocols that are used to build distributed systems.

Calculator

I found my brandless calculator in my desk. As I haven't used it in months, maybe I should take it home. It only costed about 10\$. The reason I bought it (and not some other one in the same price range) is because it has conversion between binary, octal, decimal and hexadecimal values. (And, of course, I could play this trick of converting 1026654 to hexadecimal.) As a hacker I used to use hexadecimal to decimal conversion a lot. And yes, I cannot convert 0xAF3E within 10 seconds to 44862 by heart as some people can.

Wednesday, February 21, 1996

Snow again

On Monday the winds turned again, and while I was in Darmstadt (just below Frankfurt, Germany), the northern part of the Netherlands was covered under snow again. In Enschede we only had a little, but there is snow again.

A riddle

Last Sunday, we went to Darmstadt, to stay there for two nights and days. So, my girl friend gave me two pairs of socks in a bag. I only had a small plastic bag to keep the socks in, and I was forced to use it for both the fresh and used socks.

So, on Monday morning I sat on the side of the bed and looked in the bag, containing two pairs of unused socks, and immediately saw which pair I had to pick, in order not get confused, and know which was the unused pair the next day. Now, you have to know that I have a bad memory for small details, so marking the socks (by folding them in a special way might not work). I put the new socks on, and put the used pair in the bag with the unused pair. (Notice, that however, that in case I would have had two bags, as most people do, I might have confused the bags, which would both contain one pair of socks.)

On Tuesday morning, I looked in the bag again, and I had indeed forgotten which was the used pair, or how kept them apart. But then I recalled that there was a logical way of determining which was the one that I should put on. And there was only one, and soon I knew which (clean) pair of socks I had to put on.

The riddle is: How could I have done this?

This riddle has been posted in rec.puzzles.

(follow-up)

Funny

Listen to the worlds fastest talker.

Friday, February 23, 1996

Stealing pens

I just cleaned my desk (we just finished an important
report), and found 9 pens, and a cap, partly covered under my papers. I am quite sure that it must be more than a year ago that I got some new pens. As most of them are still working, I am forced to conclude that I stole (or at least unconsciously took) them from my colleagues.

The socksriddle

So far, I did not see any solutions, except for sniffing and folding methods (which I did not use). A small hint: The riddle says that I looked in the bag, and that I immediately saw which pair I had to pick. The most obvious visible attribute of a sock is colour.

Girvies L. Davis

I found a page about him through a page about Capital punishment. Reading his Clemency Petition made a big impression on me.

I came to this page, because yesterday I send an email to The Honourable Lawton Chiles, Governor of Florida, with respect to death penalty of Ricky Roberts.

Sunday, February 25, 1996

The Wedding of the Lord

Today Eddie Bakker
preached on Revelation 19:6,7.

A traditional Jewish Marriage

Whenever a young man wants to marry a girl, he goes to visit her father, to discuss the dowry. If he and the father of the girl have agreed upon the dowry, they drink a glass of wine to seal the agreement. From that moment the young man and the girl are engaged, which is considered equal with being married. The young man goes home to build and prepare a house, which consists of one or more rooms attached to his fathers house. It is his father who determines whether the new rooms have been prepared correctly. Then the young man goes with his friends to catch his bride (together with her friends). This catching is almost a kind of stealing, and he takes her to their new rooms. After they have gone into their new rooms and they have become one in mind, body and spirit the wedding feast starts, which usually takes several days up-to several weeks, depending of the wealth of the young man.

There is a striking resemblance between this wedding tradition and the story of Jesus with the church as his bride.

• Jesus drink wine with his disciples at the last supper.
• He paid the highest price, by giving His own life.
• He returned to His Father to prepare rooms for His bride.
• He will come back, as a thief in the night, to get His bride.
• There will be a great wedding feast.

Genesis 3: The Fall of Man

Personably, I find this one of the most remarkable chapters of the Old Testament. It speaks in such an accurate way about the (fallen) spiritual state of man, that it cannot be the result of mere human thought. This is definitely one of the chapters that proved the divine inspiration of the Bible.

The three kinds of temptations

Compare Gen. 3:6, 1 John 2:16, Math 4:1-11, and Luke 4:1-13.
• The lust of the flesh. `The woman saw that the tree was good for food'. Jesus was tempted to turn stones into bread.
• The lust of the eyes. `The woman saw that it was a delight to the eyes'. Jesus was shown all the kingdoms of the world.
• The boastful pride of life. `The woman saw that the tree was desirable to make one wise'. Jesus was tempted to take pride in that the angles would protect Him from harm.

(follow-up)

Monday, February 26, 1996

The SocksRiddle

There came some answers in the rec.puzzles news group. Charles Bryant wrote:
You had two identical pairs of socks, and an extra pair. For example, four red socks and two blue. Sunday's socks were red, so you deduced that if you were to wear the blue on Monday, you wouldn't be able to tell the fresh and used red pairs apart on Tuesday. Therefore you left the blue pair for Tuesday.
Indy objected:
This would work if you had a good memory, but he stated that he had a bad memory. My assumption was that color, textures, materials (wool vs. silk) and other markings would be non-helpful; Therefore he would have to choose the new pair from current means rather that a past memory. (i.e. smelling them!). :)
David Conrad then explained:
Charles' scheme works fine without any memory of colors, textures, etc.

On the first day you wear one pair of red socks, and have a clean red pair and a clean blue pair in the bag.

On the second day you could pick either clean pair to wear next, but you realize that wearing the blue pair will leave you with a problem tomorrow, so you wear the clean red pair, putting the dirty red pair in the bag.

On the third day you don't need to remember which pair in the bag is clean. You simply compare the ones in the bag with the ones on your feet. The ones that resemble the pair you're wearing are dirty, the others (blue) are clean.

You do need to remember your reasoning from day two (which kept you from wearing the blue socks second), but you don't need to remember colors.

Bravo to all who solved it.

A small remark though: On the third day, I did not even remember the reasoning, except that it was logical. And then I deduced from this what it must have been, just like the above people solved the riddle. Actually, that I could deduce it on the second day, gave me the idea to post it as a riddle.

(follow-up)

Wednesday, February 28, 1996

The socks riddle (continued)

To what David Conrad said (see last Monday's entry), Indy replied:
Is this the Official answer? I suppose that this answer is the only true "canned" answer (even though a selective memory may rub me the wrong way).
Today, I read a posting by Seth Breidbart replying to this with:
You don't have to remember your reasoning; since it's reasoning, you can reconstruct it from scratch.
By the way, Indy mailed me (on Monday) the following, after I had replied to (by email) his posting on the news group:
Is this the Official answer? I suppose that this answer is the only true "canned" answer (even though a selective memory may rub me the wrong way). Actually he could write his reasoning on a note and tie the note to his finger, but he would have to remember to read the note! .........Thanks for your reasoning!
I replied to him (by email), and said the following:
As I am the poster of the riddle, this can indeed be considered as the official answer, although I could say some more about it. (For example, explain how other combinations of coloured socks would not have worked, and so on ...)

The fact that people were able to solve the riddle, proves that I did not need any information on Tuesday, except that there was a logical argument involved. It was then that I realized I could post it as a riddle.

A talk by Heike Wehrheim

I just came back from a talk by Weike Wehrhein about `Specifying reactive systems with action dependencies'. From the name I had not guessed that she was a woman. During the talk, I got the impression that she was pregnant. (What if I am wrong? Susan was not convinced.)

Yesterday's Fragment

The Fragment was taken from a colour picture. I do not believe that anybody can find the original picture it was taken from, although it is only about 5 steps (search engines excluded) from one of my pages.

Vanilla Tea

I made some vanilla flavoured tea for myself, which is produced in Holland by Arcus B.V. in 's-Hertogenbosch. I am just trying to get my first C++ class definition compiled, which are part of a scanner/parser for the CoCoA language we designed as part of the TransCoop project.

Thursday, February 29, 1996: Leap Years Special Day

I played with the
model train of the Univeristy of Ulm.

At the end of the afternoon, Susan came to show me a drawing [GIF] (redrawn with xfig) which she used to explain something to Jürgen. Or in other words:

Coorporation without notification implies isolation and loss of work.

(next leap day)

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