John R. Longley

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We propose a uniform way of isolating a subcategory of predomains within the category of modest sets determined by a partial combinatory algebra (PCA). Given a divergence on a PCA (which determines a notion of partiality), we identify a candidate category of predomains, the well-complete objects. We show that, whenever a single strong completeness axiom(More)
Much research in computer science, ever since its inception, has been devoted the problem: “How can we be sure that a computer program is correct?” The general problem is extremely difficult, and the enormous variety of computer software in use demands a corresponding variety of approaches: e.g. structured design methods [YC86], automated testing [Ber91](More)
A. Background A1. Introduction One of the fundamental questions at the heart of computer science is: \What does it mean for an operation or function to be computable in principle?" For the case of functions on the natural numbers, the work of Church, Turing and Kleene in the 1930s yielded several mathematical characterizations of a good class of computable(More)
A new type of urinary conduit utilizing pure carbon has been used in dogs. It appears to be inert with respect to urine, acts as an adequate conduit in dogs, and theoretically should work in humans. Twelve vesicostomies and two ileal-bladder using carbon as a conduit were performed in dogs. Evaluation of the biocompatibility of the carbon material, a report(More)
Determination of the prostatic acid phosphatase is, theoretically, a specific test for carcinoma of the prostate, but the present laboratory techniques have produced too many false positives and false negatives to be dependable. There may be inhibitors or enzymes that interfere with these tests. Until more exact enzymes are discovered, the present acid(More)