R. G. Meadows and R. Delbourgo, Advanced Pure Mathematics (Penguin, 1971), 128 pp., £2

Tight LMC massive star clusters R 127 and R 128 ?

We study the Large Magellanic Cloud (LMC) star clusters R 127 and R128 using imaging and spectroscopy obtained at the ESO NTT telescope. An advanced image restoration technique allows us to resolve these two clusters into at least 14 and 33 stars respectively and obtain their photometry. In particular, we show that the core of R 127 is composed of at least four stars and identify the Luminous B...

Indecomposability of R and R\{0} in Constructive Reverse Mathematics

It is shown that —over Bishop's constructive mathematics— the indecomposability of R is equivalent to the statement that all functions from a complete metric space into a metric space are sequentially nondiscontinuous. Furthermore we prove that the indecomposability of R \ {0} is equivalent to the negation of the disjunctive version of Markov's Principle. These results contribute to the program...

G G r Machine Repair Problem with Spares and Additional Repairman (TECHNICAL NOTE)

The machine repair problem with spares and additional repairman is analyzed. The interfailure and repair times of the units are general identical and independently distributed. The failure and repair rates are assumed to be state dependent. Using diffusion approximation technique, we obtain the queue size distribution under steady state. The average number of failed units, average number of ope...

Professor G. R. Hargreaves

G T R

We study the notion of a stub equality for a congruence generated by a ground term rewrite system (GTRS). We study the congruence generated by the union of GTRSs R and S , where the congruences generated by R and S intersect with respect to their stubs. We show that for any equivalent reduced GTRSs R and S , the same number of terms appear as subterms in R as in S . We give an upper bound on th...