“…Consequently, δ ( t ) is taken as the asymptotic identity in ( L
1 ; ∗) in the domain of generalized functions. Accordingly, the inverse of the conventional convolution discussed by, for instance, Mikusinski [112], Bracewell [115], Huang and Qiu [116], Abutaleb et al [117], Rhoads and Ekstrom [118], Todoeschuck and Jensen [119], and Moreau et al [120], exists because the necessary and sufficient condition that the inverse of an operation exists is that there exists the identity in that system, see, for example, Korn and Korn [121], Zhang [122], Riley et al [123], Bronshtein et al [124], and Stillwell [125], but it should be in the sense of generalized functions. As a matter of fact, the conventional convolution itself is in that sense, see, for example, Smith [126].…”