基本解釋

同根派生

That's examples of deductively valid arguments.
這是演繹有效論點的例子。
Now I had said some arguments are deductively valid but not in virtue of their form.
我說過一些論點是演繹有效的,但是不是它們的形式。
The only that that is important now is that you understand what a deductively valid argument is. That it is truth preserving, if the premises are true then the conclusion must be true.
現(xiàn)在唯一重要的是你們要理解,什么事演繹的有效論點，也就是真理保留，如果前提是真的，結論必定是真的。