15 Years On 15 Years On 15 Years On is the eleventh studio album by the Irish folk band The Dubliners. This album was created to celebrate the band's 15th anniversary from the day they started music together. The album was released on the Chyme label in 1977. The album features 24 tracks on two records (nine of which were previously unreleased). In spite of having only nine previously unreleased tracks, it is still regarded as an original album. The group's line-up consisted of Barney McKenna, Luke Kelly, John Sheahan and Jim McCann. (Ronnie Drew and Ciarán Bourke feature on a number of
Opposite group Opposite group In group theory, a branch of mathematics, an opposite group is a way to construct a group from another group that allows one to define right action as a special case of left action. Monoids, groups, rings, and algebras can be viewed as categories with a single object. The construction of the opposite category generalizes the opposite group, opposite ring, etc. Let formula_1 be a group under the operation formula_2. The opposite group of formula_1, denoted formula_4, has the same underlying set as formula_1, and its group operation formula_6 is defined by formula_7. If formula_1 is abelian, then