to simply say that the speaker must be lying in either part or a b doesn't satisfy the fact that it can be considered a true paradox rather than a physical error whether intentional or not consider that part is just an affirmation of something which is recognised to be true part is affirmed by the speaker as a statement to alert others to a form in which they would understand such as it is raining part then simply has to be the affirmation of what the speaker believes to be true rather than a conveyed message of indication