ExpressionJ 是一个用来解析简单的算术表达式的 Java 类库。
1. 新增 INTEGER 和 FLOAT 变量类型.
2. The package for fundamental Objects definitions was changed.
3. The expr package is... now only for mathematical expressions.
4. The concept of global constants was added.
5. Beware that this release may break some of the code defined with the previous one because of the change of the package t=for the Variable class