  Like Gupta and Belnap, Yaqūb posits no privileged extension for T. And like Gupta and Belnap, he sees the revision sequences of extensions of T, each sequence generated by an initial hypothesized extension, as “capable of accommodating (and diagnosing) the various kinds of problematic and unproblematic sentences of the languages under consideration” (1993, 41).  But, unlike Gupta and Belnap, he concludes from these considerations that “truth in a bivalent language is not supervenient” (1993, 39). He explains in a footnote: for truth to be supervenient, the truth status of each sentence must be “fully determined by nonsemantical facts”. Yaqūb does not explicitly use the notion of a concept's signification. But Yaqūb seems committed to the claim that the signification of T — i.e., that which determines the truth status of each sentence — is given by a particular revision sequence itself. And no revision sequence is determined by the nonsemantical facts, i.e., by the ground model, alone: a revision sequence is determined, at best, by a ground model and an initial  hypothesis.[9] 