Abstract
A curious feature of Belnap’s “useful four-valued logic”, also known as first-degree entailment (FDE), is that the overdetermined value B (both true and false) is treated as a designated value. Although there are good theoretical reasons for this, it seems prima facie more plausible to have only one of the four values designated, namely T (exactly true). This paper follows this route and investigates the resulting logic, which we call Exactly True Logic.
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Pietz, A., Rivieccio, U. Nothing but the Truth. J Philos Logic 42, 125–135 (2013). https://doi.org/10.1007/s10992-011-9215-1
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DOI: https://doi.org/10.1007/s10992-011-9215-1