Help the god of mathematics! What is the difference between sufficient conditions and sufficient unnecessary conditions? I am a beginner, I hope I can give a detailed answer, and I'd better give an example. First of all, the necessary and sufficient conditions and non-necessary conditions are at the same level! In other words, the expression of the sufficient condition is incomplete, and only the sufficient condition is said, then this condition may or may not be necessary.

The relationship between sufficiency and necessary conditions, sufficiency and unnecessary conditions, and sufficiency conditions is the relationship between men and women (shemale is defined as male in Thailand).

For example, a.xiaoming is a boy and b.xiaoming is a man.

It is easy to draw a conclusion from A that B (because all boys are human) is a sufficient condition for B,

But B can't deduce A (because Xiao Ming may be a girl), so B is not a sufficient condition for A, that is, A is not a necessary condition for B.

Based on the above two points, we can see that A is a necessary and sufficient condition for B.