This kind of rule is found in expert systems , knowledge bases, and logic texts/ tests. And (some say) in people's heads.

"Rule" in the context of expert systems and knowledge bases is usually used to refer to statements that use logical implication -- if A, then B. This can be written

  A -> B

Or, for a more concrete (albeit fanciful) example,

   X is a polar bear -> X works for Coca Cola

If you have a system with an inference engine that knows this rule, and it learns that Ferdinand is a polar bear, it can use the rule to infer that our pal Ferdinand is getting his blubber money from the Coke guys.