Yep, it's yet another rule of inference used in propositional logic. It is written as Imp or Impl for short.

(P→Q) = (¬P∨Q)

(P therefor Q) = (either 'not P' or Q)

Or in English:

*If it rains (P), then I'll get wet (Q).*

is the same as...

*Either it won't rain (~P), or I'll get wet (Q).*

Back up to Rules of Inference

Review your Logic symbols