$\newcommand{\defeq}{\mathrel{\mathop:}=}$

## 2012/09/28

### 備課

[...] [N]atural deduction [...] follows the way people reasoned before it was tried to explain logic by means of an algebra of truth values. Such Boolean logic is the metatheory of classical reasoning. It does not show what that reasoning is. It is silly that education in elementary logic so often takes truth values as the point of departure.

The idea that truth values are the basis of logic may have been one of the reasons why Brouwer's rejection of the law of the excluded middle was so little understood in his time. If one starts from Boolean logic instead of from natural deduction it is impossible to understand what that rejection means.

### 聽課

scm 老師臨危受命，除了本來的 program construction 以外又接下 functional programming. 不知道 scm 老師在資管系受到什麼樣的打擊（或啓示），上課速度慢得不可思議。我私下向人解釋 Church numerals 的時候順便講了一下 fold, 以為破了 scm 老師的哏，結果十八小時的課別說 fold fusion, 連 fold 都沒真的講。Fold 算是學 FP 必撞的一道牆，既然如此不是應該編入課程幫助學生跨越嗎？而且我還是覺得沒有講 fold 的 FP 只是讓人稍微嘗鮮，跳不到全新的角度看編程。不過在意見調查表上 scm 老師的課得到一致好評，讓學生容易聽懂的設計確實有成功。另外邪教說已經成為 FLOLAC（海洋年？）傳統，今年邪教檢查表堂堂進佔意見調查表最後一頁，scm 老師更正式坐上邪教教主大位，可喜可賀 XD。

### 教與學

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28 Sep 2012: 抵英兩週年紀念日。

Wen-Shih Chao9/29/2012 2:40 am 說：