As previously mentioned, I am learning category theory, beginning with Lawvere's Conceptual Mathematics book. This is a very elementry book that assumes almost nothing as a background. However, it is still a math book, which requires doing some exercises. Since the book provides no answer to exercises, I decide to make my own and post them here as I did them. Hopefully someone will find them useful.
For people that need full features of vim, the default installation of vim on Mac OS X is definitely not enough. For example, I need to use vim to post to this blog, which requires a version of vim with python support. I also prefer terminal version of vim to the GUI version, so MacVim is less desirable.
One way to get what I want is to compile a version of vim with homebrew. Homebrew does not officially have a vim fomula, because that would be a duplicate of the system version. Fortunately, we can grab an unofficial formula at
Perhaps due to my rather small brain (literally), I dislike remembering tedious details. When in elementary school, I hated reciting classic Chinese poems, but liked composing my own :-). In high school, I hated chemistry but loved physics, because one could do everything based on a few principles in physics, whereas chemistry was all about memorization. Last year, I was chatting with a colleage of mine who had a Ph.D. degree in chemistry from Harvard. He said he's good at it because he could find patterns in all the tedious details and summerized them in his own head, so he didn't have to remember them all. So I said why not write those patterns down so others can benefit, and he didn't seem to like that idea. Anyway, let's go back to the main topic.
When Tom (唐唐）was adopted from the animal shelter, his papers listed him as an "American Domestic Long Hair". As new cat parents, we were eager to find out his true breed. We searched and searched online, and identified him as a Chartreux, based on his fur color and personality. We knew that Chartreux is a short hair cat but Tom has long hair, but we thought Tom must not have been a pure breed. We always joked about Tom's purpoted French origin and attributed his love of bread and butter to his French ancestry.
Updated on 09/10/2013: It's now only 295 USD, with 100 USD discount!
As a cat and modern design lover, I am always looking for cat items pleasant for both the cats and my aesthetic standard. I had my eye on the canine scratcher for a while, but its over 1000 USD price tag made it out of reach. However, recently, I found that it now costs "only" 395 USD. I pulled the trigger w/o too much hestitation since I need to buy the cats a holiday present anyway. However, I was still a little nervious at the purchase, as it would be a huge bummer if the cats don't like it. But I really love the design and can totally see how it fit with the rest of the house w/o screaming "cat furniture".
I was brought up as a Han Chinese and I myself have never doubted that identity. However, I do know that I look slightly different from people around me when I grew up. Darker skin, slightly curly hairs, deeper set eyes and other distinctive facial features. Put it simply, my face does not look like an average Han male face. However, nobody really said anything about my appearance except that my old brother occasionally joked about it (he looks like a normal Han Chinese by the way). After all, I look just like my father.
I recently stayed in Manhattan for a few days during a business trip. My colleague and I were looking for places to buy some special chocolate to bring back home. We asked a few locals New Yorker as well as consulted the web for recommendations. Here are the list of stores we collected.
We only have 3 hours to spend in the city. So we went to La Maison Du Chocola store in the Rockefelle Center, the store closest to our hotel.
As many of friends, I recently acquired a HP Touchpad largely due to its low price. I don't really need a tablet, as I am sitting in front of computes almost all the time. My original plan was to turn it into an interactive cat toy, at least sometimes, so I can keep the two cats entertained while I am working.
Unfortunately, I could only find one game designed for the cats "The Catnip Collection". According to its website, it "is a variety of toys that will amuse and challenge your cat and its human".
The reviews seem pretty decent (4 out 5).
Huahai and I have just returned from our first trip together to Italy. The trip itself was wonderful and unforgeable. However, it usually took a lot of planning for such an extensive trip, unless you hire someone else to do it for you or join a tour group.
We usually enjoy traveling at our own pace and explore the area; therefore, we (basically myself) always do our own travel planning. Unfortunately, as a very busy professional, I do not really have much time to do the planning. (Can you believe someone have actually spent half a year to plan a two-week's trip to Italy and produce a travel plan with 90 pages?)