Conditional Statements with various phrasings -- PLEASE HELP

[PatMcGroin]

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

Thanks a lot!

[KelseyWoods]

Hi Pat!

A requires B = A needs B = A necessitates B = All that is required for A is B = A B
These statements are all saying the same thing--that A needs B. In other words, B is necessary for A. Thus, B is the necessary condition and goes on the necessary side of our diagram (at the end of the arrow).


A is necessary for B = A is required for/by B = B A
These statements are saying that A is the necessary condition. A is necessary/required for B. Thus, A goes on the necessary side of our diagram (at the end of the arrow).

When you are reading phrases like this, really think about which condition is necessary for the other one. Whichever is the necessary condition always goes at the end of the arrow.

Hope this helps!

Best,
Kelsey

[PatMcGroin]

Hi Kelsey,

Thanks for your response. One more question:

in case of where a conditional statement has "No one", "None", or "Nothing", does that imply a double-not arrow? For example, No A is B would mean A B ?

Also would "cannot" imply the same thing? Ex. A cannot be B = B cannot be A?

[Dave Killoran]

Yes, those are both correct