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Happy Holidays December 25, 2009

Posted by Elfi in Life and everything.
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It is the first Christmas time I am spending with Hanka. It is quite special. In the past, we always traveled to Czechia and spent the Christmas day with our respective parents. For this year we have decided to stay in Sweden and celebrate together. We have a great time and so far we have saved ourselves a lot of tiredness from traveling. Love it. We plan to travel to Czechia right after holidays and before the New Year’s Eve.

Happy Holidays to one and all!

Tonight I will win the board game Fury of Dracula for the fifth time in a row. Never beaten yet 🙂


A Week in Bullets December 17, 2009

Posted by Elfi in Life and everything.
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  • I read a lot. I am hungry for more category theory and computability. Linear logic and Geometry of Interaction is lurking around the corner.
  • I went to see the big GöteborgsOperan’s stage featuring a dance performance on Mozart’s Requiem. It was a nice evening. Yet, I wished more space was given to the orchestra. The dancers seized way too much attention.
  • I find out my fingers got stronger for more climbing, though training on the hang board has to wait.
  • I have got a cold.

Morning Shifts December 12, 2009

Posted by Elfi in Life and everything.
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I feel like a zombie these days. And it is weekend so it should not be that way. The problem is that it has been for two weeks now I am commuting every day to Goteborg with Hanka and I am forced to get up at 7:45 – 8am instead of at my usual time 9 – 9:15am. In the morning itself, it is not too bad. I can get up quite easily and I am looking forward for the day but then, around lunch time, my activity starts to drop. Lunch makes me more alert again for a while but around 3pm I am a zombie. Not really tired, not sleepy, but apathetic, brain death, physically weak. It gets better again at 9-10pm which is kind of late. In the past, I have used to be agile from 9am to 1am. So the number of active hours dropped enormously.

I always had problems with sleeping and it turned out that as long as I can sleep from 6am to 9am, my best quality sleeping time, I will do fine regardless of when I go to bed. I really miss the hour of sleeping I am not allowed to have now.

Other effect of getting up early during workdays is that you get up early also during weekends and so you get some extra amount of hours of zombie time. Great 😦 .

I hope I will get my hour back soon or I will adapt without becoming a mediocre being drinking coffee every two hours just to get the work done and survive the day.

By the way, wet, wet cold weather is back. Given my current state of mind I cannot do much better than drink a hot tea, look at the exotic fruit and think of warmer places to be in.

Rävlanda is Freezing December 3, 2009

Posted by Elfi in Life and everything.
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After quite some time of endless rain a bright blue sky is back. At least for today. Soaking wetness was cut down by temperatures around minus eight degrees Celsius. It took some courage to get off my bed in the morning. Not that it was any kind of surprise. I have yet to master how to pretend this activity 🙂

Berg Bergagården in Rävlanda, Sweden. December 2009.

Photo: Miroslav Dobšíček

New Things to Learn November 29, 2009

Posted by Elfi in Research.
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I have been twiddling with computability, mathematical logic and category theory for the past few months. I was very happy to find this area since no Web 2.0 related technology, Java 7 or software engineering in general light a spark of interest in me.

So, my plan is to work through N.J. Cutland’s Computability, S. Awodey’s Category Theory and selected papers of S. Abramsky, consult a lot with people at The Programming Logic Group in Göteborg and back up my understanding via the ways of programming in Haskell, Coq and Agda. The goal is to find new connections between computer science and physics. This ties nicely with quantum computing and algorithms I was involved with during my PhD period.

Yeah, and these books I would like to read too.

It feels good to get up in the morning so much inspired and looking forward to the day.

A follow up


20 Years On November 20, 2009

Posted by Elfi in Life and everything, Music.
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Time flies. It has been 20 years since the Velvet Revolution in the former Czechoslovakia, 20 years since I was a fifth grade grammar school disciple.

Little me in a summer camp with my brother Pavel on the right, Helvíkovice, Czech Republic. Around 1987.

Photo: Jarmila Dobšíčková

The above picture is quite remarkable. On the inner side of the tent canvas you can see a reflection of my mom’s hands, hair and a camera.

Some memories. In 1989, those 20 years ago, we have started with the Russian language at school. We were shown beautiful maps proving that Russian is spoken everywhere around the world, with off course the USA crossed out as a dummy country unwilling to learn and herewith contribute to the world peace. I doubted how much Russian is actually spoken in the South America, but what the heck …. I was kind of looking forward. In two months, we have almost mastered the Cyrillic alphabet but then it changed.

Friday, November 17, 1989, was just an ordinary school day for me and during the weekend merely some scattered news about people ‘shambling’ in Prague reached me. People of Prague, don’t they have better things to do? They should come and help us on the country side. OK, OK:-) , enough sarcasm and making fun from my childish perception of those important days.

To make a long story short, Russian lectures were canceled in few days, being replaced by very bad English lectures or rather good German ones, school was full of leaflets “Havel na hrad” (Havel for president) and not that long afterwards all adults around got puzzled by a voucher privatization.

I have a memory of admiring people around me, particularly my parents. It was very special to witness what Anton Chekhov wonderfully put as

Any idiot can face a crisis, it’s the day to day living that wears you out.

I feel so thankful for what happened, for all the wearing out and the new direction.



Me and my wife, we both celebrated by visiting a punk party. The Eastpak Antidote Tour reached Gothenburg. Good music. And great people around make you almost forget how bad the local beer is 🙂

Source: Wikimedia

I was giving a talk at Chalmers University the next day and I was a little bit behind with preparation of my slides but everything worked out fine at the end.

The World is Big November 16, 2009

Posted by Elfi in Movies.
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and Salvation Lurks Around the Corner, 2008, Bulgaria. A very warmhearted movie climbing across the life behind the iron curtain in Bulgaria, West Germany and back in “New” Bulgaria. I have seen this movie at the Göteborg International Film Festival and it seemed many people liked it. It is relaxing and full of a very spectacular charm.

A very strong passage is a ‘temporary’ stay of the main characters in an Exile Camp in Italy. For some a place they never left.


Miki Manojlović stars and makes you know what kind of person you want to be. Eventually, you might want to blow dust off your bike. Don’t fight it 🙂

Random links November 9, 2009

Posted by Elfi in Computers, Life and everything.
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September 2009

Publishers of all types, from news to music, are unhappy that consumers won’t pay for content anymore. At least, that’s how they see it.

In fact consumers never really were paying for content, and publishers weren’t really selling it either. If the content was what they were selling, why has the price of books or music or movies always depended mostly on the format? Why didn’t better content cost more?

Paul Graham

June 2009

Code and program are the same; any fragment of code may be used interactively. Complex programs are just compositions of simpler ones, and composition of programs is a fundamental concept to both users and programmers. Thus power users cannot help but to be programmers.

Computer science has become a strict subfield of applied mathematics. Creating complex software is primarily modeling: the fundamental task in software development is to create a mathematical model of your problem. The model is encoded directly, and then software scaffolding is built around it, verified to the model. Reasonable shops do not dare ship code that hasn’t been verified to correspond to their model.

Luke Palmer

May 2009

Someone claimed that OOP made it easier for programmers to develop large applications from components. I have been thinking about this claim for the last several weeks. There are two parts to this claim. One is that programmers began to develop large applications more easily from components at the time OOP became popular. Two is that OOP was the what allowed ease of development.

I am not certain either claim is true. I did find it hard to believe that OOP could be responsible for improving productivity. When I think of OOP what comes to my mind is virtual method specialization/dynamic dispatch.

Dynamic dispatch is a scary programming technique. When you call a virtual method, you never know what might happen. This makes it difficult to reason about such code, and code that is hard to reason about is hard to maintain. Dynamic dispatch has its uses, but they are relatively limited. I feel that OOP style encourages this dangerous technique, and it ends up being abused. How could a programing technique that is so dangerous be responsible for improving programmer productivity?

Russell O’Connor

January 2004

Have you ever seen an old photo of yourself and been embarrassed at the way you looked? Did we actually dress like that? We did. And we had no idea how silly we looked. It’s the nature of fashion to be invisible, in the same way the movement of the earth is invisible to all of us riding on it.

What scares me is that there are moral fashions too. They’re just as arbitrary, and just as invisible to most people. But they’re much more dangerous. Fashion is mistaken for good design; moral fashion is mistaken for good. Dressing oddly gets you laughed at. Violating moral fashions can get you fired, ostracized, imprisoned, or even killed.

Paul Graham

Running Arch Linux November 8, 2009

Posted by Elfi in Computers.
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I have been a Linux/GNU user for about 10+ years now. My first distribution was Red Hat Linux and it did not last long. After a couple of days I was tired of troublesome circular dependences between packages and it was time to check the market more carefully.

Strahov Campus, Prague, Czech Republic. Around 2003.

StrahovPhoto: Miroslav Dobšíček

One evening, after a particularly bright day at Strahov Campus,
I commended to a friend of mine, Karel, who at that time was a guru – only a guru could run Red Hat for more than about two weeks without loosing his mind (he only stopped smoking, drinking and failed few exams later on) – and he told me “Elfi, look, install Debian and you will become a real bushranger”. Of course, he was ironical, smiling and what he really meant was that only a village feeble-mind would leave Red Hat behind. So I did 🙂

Debian proved to be an excellent choice and still it is. I never had to reinstall anything, no single unexplainable failure.  However, as time passed by, a robust and well rounded distribution such as Debian was becoming slower and slower on my laptop with new upgrades. At some point, when the hard drive stopped working to be more precise (read: when I lost a lot of data being laggard to pursue a back-up hard drive instead of an occasional  DVD burn), it was time to give a try to Arch Linux.

Installation was not so straithforward as with Debian since from the time of Lenny “a chicken could install Debian if you put enough grain on any key”, but nevertheless it worked quite well.  It would have been nice to distribute “how-to” documents along with the installation image. Having problems with the X Window System I had to navigate Links to the http://www.archlinux.org site which kind of slowed the installation down. Especially, if the very first issue you have to deal with is a non-working wireless network interface.

Now, I am running Arch Linux for about a month and so far I can only say that it rocks! I gained a lot in terms of speed and the distribution stands to its slogan “simple and lightweight”. Time will show how stable it actually is since new packages are provided daily in a rolling style. Right now, I worry a little bit every time there is a new Linux kernel or X.Org delivery. Things are radically different from Debian stable releases.

A screen shot of my Xmonad session running unicode-rxvt terminal, VIM text editor and Firefox 3.5.

xmonad-screenshotClick to enlarge


Some of my current settings:  

xsetroot -cursor_name left_ptr
exec ck-launch-session xmonad


URxvt.buffered: true
URxvt.background: white
URxvt.foreground: black
URxvt.underlineColor: yellow
URxvt.font: xft:DejaVu Sans Mono:pixelsize=12
URxvt.boldFont: xft:DejaVu Sans Mono:pixelsize=12
URxvt.perl-ext-common: default
URxvt.title: urxvt


import XMonad
import XMonad.Hooks.ManageDocks
import XMonad.Hooks.DynamicLog
main = xmonad =<< xmobar defaultConfig
{ terminal = "urxvt"
, manageHook = manageHook defaultConfig <+> manageDocks


set linebreak
set showmode
set showcmd
set smartindent
"set background=dark
"colorscheme torte
highlight Statement ctermfg=Yellow
set mouse=v
set wrap
set nopaste
set ruler
set viminfo='50,\"500
set history=50
set wildchar=
set wildmenu
set wildmode=longest:full,full
set display=lastline
set showmatch
let g:calendar_monday = 1
let g:Tex_DefaultTargetFormat='pdf'
let maplocalleader = ",,"
set tabstop=2
set smarttab
set shiftwidth=2
set autoindent
set expandtab
syntax on
filetype plugin on
filetype indent on
set fileencodings=utf-8
:map :set hls!^M
:map :set paste!^M
:map gq}{

Climbing on Kalymnos November 4, 2009

Posted by Elfi in Books, Climbing, Travelling.
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It was great 10 days at Kalymnos, Greece. Me and Hanka had so much fun. I managed to enter the grade 7a with a couple of on-sights at this level (including wished DNA) and Hanka earned the title ‘Blu Swiss Baby Ekavi The Monohiki Hatrefa, Resista‘ resembling the names of routes she successfully or nearly successfully leaded. It was a big step for her since she mostly did top rope in the past.

Happy after climbing DNA 7a, Grande Grotta, Kalymnos. October 2009.

dsc06883Photo: Hana Trefná

Hanka climbing Harakiri 6b, Spartacus, Kalymnos. October 2009.

dsc06964Photo: Unknown climber, thanks!

Climbing Ivi 7a+, Grande Grotta, Kalymnos. October 2009.

dsc06973Photo: Unknown climber, thanks!

Climbing Ivi 7a+, Grande Grotta, Kalymnos. October 2009.

dsc06976Photo: Unknown climber, thanks!

Climbing Ivi 7a+, Grande Grotta, Kalymnos. October 2009.

dsc06968Photo: Unknown climber, thanks!

Port in Pothia, Kalymnos. October 2009.

dsc06922Photo: Miroslav Dobšíček

Convent of Agioi Pantes in Pothia, Kalymnos. October 2009.

dsc06926Photo: Miroslav Dobšíček

The second day off out of two at total I spent at sofa reading Milan Kundera‘s Žert (The Joke) from cover to cover. I liked the book very much. It is quite similar in many aspects to his other novel Nesnesitelná lehkost bytí (The Unbearable Lightness of Being). Existentialism without a message …, wonderful.