Function of a Parser Takes the sequence of tokens produced by the scanner as its input and produces the syntax tree as its output. Parser Sequence of tokens Syntax-Tree

Basic antenna operation Receiving and transmitting antennas are identical: Time just flows in opposite directions. Antenna problems are solved knowing the current distribution J(x') in the antenna and using a vector potential

Main idea LL(1) Parsing uses an explicit stack rather than recursive calls to perform a parse An example: – a simple grammar for the strings of balanced parentheses: S→(S) S∣ε The following table shows the actions of a top￾down parser given this grammar and the string ( )

Why Compiler Writing machine language-numeric codes is time consuming and tedious

5-1 MCS-51单片机最小系统 5-2 存储器的扩展 5-4 可编程并行接口芯片8255A 5-6 常用通道配置与接口技术 5-7 D / A转换 5-3 并行I / O端口的扩展方法 5-5 可编程并行接口芯片8155 5-8 A / D转换

5-1 MCS-51单片机最小系统 5-2 存储器的扩展 5-4 可编程并行接口芯片8255A 5-6 常用通道配置与接口技术 5-7 D / A转换 5-3 并行I / O端口的扩展方法 5-5 可编程并行接口芯片8155 5-8 A / D转换

Elasticity . . . … is a measure of how much buyers and sellers respond to changes in market conditions … allows us to analyze supply and demand with greater precision

In a free, unregulated market system, market forces establish equilibrium prices and exchange quantities. While equilibrium conditions may be efficient, it may be true that not everyone is satisfied

The Law of Supply: uFirms are willing to produce and sell a greater quantity of a good when the price of the good is high. uThis results in a supply curve that slopes upward

晶体中原子的周期性排列形成了晶体一定的宏观对称性，不同的形式的原子排列形成的宏观对称性， 其对称操作也具有一定的限制。 描述晶体周期性的布拉伐格子：{ } 1 1 2 2 3a3 l a l a l K K K + + —— 经历对称操作后晶体不变，相应的布拉伐格子也不变