 According to the modality interpretation, Peirce’s “lower mode of being P” means P not being actual, and Peirce’s third value L, being potential, is “at the limit between P (i.e., T) and not P (i.e., F)”. Later in the paper, suggesting a possible relation between Peirce’s triadic logic and MacColl’s implication (as opposed to material implication), the authors make an interesting remark: 