The most notable contrast between Program L and Program M is the fact that Program M must consider the case of an empty list, when no comparisons are to be made.

刚看到这句英文时,就感觉译文可能要出错,找出中文版一看,果然:

在程序L和程序M之间最值得注意的差别在于这样一个事实,即当不需要进行比较时,程序M必须考虑一个空表的情况。