about diagram of Conditionality

As is known to many of us, "A is sufficient for B" is considered conditionality and thus can be diagramed as A-->B. My confusion lies in the negation of the sentence "A is not sufficient for B". What is the correct formulaic diagram? Obviously I am not leaning toward A -->B; According to Logic Reasoning Bible, to negate conditionality is to negate its necessary condition, so if  "A is not sufficient for B" is the negation of the conditionality, which seemingly makes sense to me, is the diagram of "A is not sufficient for B" A-->B  ? I am a bit at a loss, could any one help me out?

I do appreciate it.