As discussed in my Pedagogical lecture: We need expression for the non-forward matrix elements of the energy momentum tensor t . Although t transforms as a tensor under Lorentz transformations, its non-forward matrix elements do not. Erroneously assuming that they do led to the incorrect expression for the angular momentum expectation value for a transversely polarized nucleon: ⟨Ji⟩incorrect = ...

In the original version of this article, unfortunately Fig. 3C and 3F were published with incorrect version. The correct are given below. This has been corrected by publishing correction article. article corrected.

In the original version of online article some entries appeared in wrong column. Following is corrected table. The has also been corrected.

Event-B does not provide specific support for the modelling of problems that require some structuring, such as, local variables or sequential ordering of events. All variables need to be declared globally and sequential ordering of events can only be achieved by abstract program counters. This has two unfortunate consequences: such models become less comprehensible — we have to infer sequential...

In 1980 Piere Duchet conjectured that odd directed cycles are the only edge minimal kernel-less connected digraphs i.e. in which after the removal of any edge a kernel appears. Although this conjecture was disproved recently by Apartsin, Ferapontova and Gurvich (1996), the following modiication of Duchet's conjecture still holds: odd holes (i.e. odd non-directed chordless cycles of length 5 or ...