“…For example, the first group of results concerning the stability of autonomous singular distributed parameter system (2) are obtained by using C 0 -semigroup [2][3][4][5][6][7]; the second group of results concerning the stability of autonomous singular distributed parameter system (2) are obtained by using degenerate C 0 -semigroup [1,8,9,11]; the third group of results concerning the stability of autonomous singular distributed parameter system (2) are obtained by using GE 0 -semigroup (i.e., strongly continuously generalized operator semigroup [10]. But there are essential distinctions among C 0 -semigroup, degenerate C 0 -semigroup and GE 0 -semigroup [1,[10][11][12][13][14][15][16]. GE 0 -evolution operator is very important for studying the time varying singular distributed parameter system (1), and there are essential distinctions between GE-evolution operator and evolution operator [14,[16][17][18][19][20][21][22][23][24][25].…”