Diagraming conditional statements with different phrases

Terry Wrist

Wondering if I can get some clarification on these, or if any of the diagrams are wrong?

A requires B = A --> B
A is required for/by B = A --> B
A is necessary for B = A --> B
A necessitates B = A --> B
A needs B = A --> B
All that is required for A is B = A --> B

Also, how could one use require/necessary such that it is B --> A, with B appearing in the sentence first?

Thanks a lot!

noonawoon

A is required for/by B = A --> B
A is necessary for B = A --> B

^I would change these. If A is required by B, then B -> A. Same with the second one