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It may mean either of two things: either that x presupposes, in the sense that x requires y by a specific and definite necessity:, or that x anticipates y, in the sense that x requires y by only a generic and indefinite necessity. (Perhaps another way of explaining what is meant by the two things that implication may mean—i.e., presupposition and anticipation—is to say that, whereas the implication rightly distinguished as "presupposition" is unconditional, the implication rightly distinguished as "anticipation" is conditional.)

7 October 2008; rev. 15 August 2009