It depends on what the subject is. Keeping it as simple as possible, we take Fact A. If we're talking about a specific fact (in this case, Fact A) then to stat

It depends on what the subject is. Keeping it as simple as possible, we take Fact A. If we're talking about a specific fact (in this case, Fact A) then to state Fact A and assert its validity/soundness/truth etc is not to lie. If the subject is not Fact A, but Fact A is is given to support a certain other position/fact with regards to the subject and you know that to say Fact A without Fact B (C, D…) will give a misleading impression about the subject then you are, indeed, lying.