“…If A is triangle, then one can easily observe that the sequence spaces X A and X are linearly isomorphic, i.e., X A = X. The idea constructing a new sequence space by means of the domain of a triangle matrix was employed by Wang [48], Ng and Lee [43], Malkowsky [29], Altay and Başar [1,2,3,4,5,6,7,8], Malkowsky and Savaş [33], Başar¬r [17,18], Başar¬r and Kay¬kç¬ [19], Başar¬r and Öztürk [20], Kara and Başar¬r [21], Kara et al [22], Ayd¬n and Başar [9,10,11,12,13], Başar et al [16],Şengönül and Başar [47], Altay [1], Polat and Başar [44] and, Malkowsky et al [30]. Additionally, c 0 (u; p) and c(u; p) are the spaces consisting of the sequences x = (x k ) such that ux = (u k x k ) is in the spaces c 0 (p) and c(p) for u 2 U, the set of sequences with non-zero entries, respectively, and studied by Başar¬r [17].…”