Deductive Logic has three parts to it which is Syllogism, Modus Ponens, and Modus Tollens.
Syllogisms
All dogs smell
Calcetín is a dog
Calcetín smells
In this part, we use the formula A=B B=C C=A. In this example A would be "dogs" while B is "smell" and C is Calcetín.
Modus Ponens
If I start to draw,then my hand will explode
I start to draw
Therefore, my hand will explode
For this part, its hard to explain but easier to understand. Its almost like a cause and effect concept in which you understand that if i do this then there is this.
Modus Tollens
If I'm on my period, then i'm wearing a pad.
I'm not wearing a pad.
Therefore, I'm not on my period.
This part is similar to that of the modus ponen. The difference is that it has you understand the negative part of it. By this I mean that, you understand that if you do this then you do that. Buuut your not doing this so your not doing that