For example, "I love eating green apples" infers that "I love eating apples" can lead to the latter, but the latter cannot lead to the former. Therefore, the former is a sufficient but not necessary condition for the latter. 1. If the conclusion q can be derived from the condition p, then the condition p is a sufficient condition for the conclusion q ... 2. If the condition p can be derived from the conclusion q, then the condition p is a necessary condition for the conclusion q ... It is a necessary and sufficient condition if both of them are satisfied.