程序以操作表达式的形式呈现， 而其语义则以公理的形式给出。

Programs have appeared as O_expressions(expressions of operations on physical objects) and program semantics are given by axioms on O_expressions.

youdao

设想一个逻辑操作表达式，例如port . signal . send 。

Imagine a logical action expression, such as port.signal .send .

youdao

如果您不能够弹出两个操作数，后缀表达式的语法就不正确。

If you could not pop two operators, the syntax of the postfix expression was not correct.

youdao

I gave it an expression that had an operand in there.

我写了一个表达式,然后这里又个操作。

麻省理工公开课 - 计算机科学及编程导论课程节选

Turns out with a Boolean expression, you don't have use the equality operator equals equals, you can just say what you mean.

结果用一个bool表达式，你不需要使用等号操作符“==“了，你只要说出你的意思。

哈佛公开课 - 计算机科学课程节选

And in Python the expression is, operand, operator, operand, when we're doing simple expressions like this, and if I give it to the interpreter, it gives me back exactly what you'd expect, which is that value. OK?

在Python中表达式就是，运算对象，操作符，运算对象，当我们处理这样的简单表达式的时候，我把表达式传给处理器，处理器给我返回了我想要的结果，对不对？

麻省理工公开课 - 计算机科学及编程导论课程节选