1.为什么说在决定生产和消费时,相对价格比绝对价格更重要? 答案提示:当生产处于生产边界线上,资源则得到了充分利用,这时,要想增加某一产品的 生产,必须降低另一产品的生产,也就是说,增加某一产品的生产是有机会机本(或社会成 本)的。生产可能性边界上任何一点都表示生产效率和充分就业得以实现,但究竟选择哪 点,则还要看两个商品的相对价格,即它们在市场上的交换比率

Slide l.l.1 This first thing we need to do is discuss the focus of 6.001 What is this course all about? This seems quite obvious-- this What is the focus of 6.001 is a course about computer science. But we are going to claim This course is about Computer Science in a rather strange way that this is not really true

6.001 Structure and Interpretation of Computer Programs. Copyright o 2004 by Massachusetts Institute of Technology 6.001 Notes: Section 3.1 Slide 3.1.1 This Lecture In this lecture, we are going to put together the basic pieces of Scheme that we introduced in the previous lecture, in order to

6.001 Structure and Interpretation of Computer Programs. Copyright o 2004 by Massachusetts Institute of Technology 6.001 Notes: Section 5.1 Slide 5.1.1 In this lecture we are going to continue with the theme of building abstractions. Thus far, we have focused entirely on Procedural

6.001 Structure and Interpretation of Computer Programs. Copyright o 2004 by Massachusetts Institute of Technology 6.001 Notes: Section 7.1 Slide 7.1.1 In the past few lectures, we have seen a series of tools for helping us create procedures to compute a variety of Good programming practices

6.001 Structure and Interpretation of Computer Programs. Copyright o 2004 by Massachusetts Institute of Technology 6.001 Notes: Section 8.1 Slide 8.1.1 Review: data abstraction In this lecture we are going to introduce a new data type, a data abstraction consists of: specifically to deal with symbols. This may sound a bit odd, but

6.001 Structure and Interpretation of Computer Programs. Copyright o 2004 by Massachusetts Institute of Technology 6.001 Notes: Section 10.1 Slide 1o.1.1 Table: a set of bindings Over the past few lectures, we have introduced the concepts of data abstractions, types and aggregate structures. In this lecture

6.001 Structure and Interpretation of Computer Programs. Copyright o 2004 by Massachusetts Institute of Technology 6.001 Notes: Section 31.1 Slide 3l.ll Trees, graphs and Search In previous lectures we have seen a number of important themes, which relate to designing code for complex syste

luse this is the central part of the environment model, let's look in very painful detail at an example of an evaluation. In (square 4)I g particular, let's look at the evaluation of (square 4)with x;10 respect to the global environment. Here is the structure we start

Slide 14.1.1 Elements of ooP Last time we introduced the idea of object oriented systems Today, we want to build on those basics, looking at how we can expand object-oriented systems to deal with hierarchies of objects, to leverage the commonality of methods between