Writing\Proposition\Implies

The implication truth-functor.  Its truth-table is:

Often implication truth-functors are mistakenly interpreted as denoting causality; they should rather be seen as indicating correlation.  In this case Y cannot be true without X also being true.  Thus it is possible that X is a sufficient cause of Y, but it may not be.  If it is intended to assert that X causes Y this should be claimed explicitly in a declarative statement.