On to the answers. You do not need to provide the return type of a lambda function; it is deduced from the return statement.
不需要为 lambda 函数提供返回类型;根据返回语句推导出返回类型。
In the execution of such a program, an input statement can be logically deduced from other statements in the program. Many artificial intelligence programs are written in such languages.
在这样一个程序的执行过程中,一条输入语句可以按照逻辑从程序中的其他语句推断出来。许多人工智能程序使用这种语言编写。