“…If holds, then T α , β generates, on L 1 , a C 0 ‐semigroup T α , β =( T α , β ( t )) t ≥0 . Furthermore, - If holds, then V α , β generates a C 0 ‐semigroup V α , β =( V α , β ( t )) t ≥0 .
- If and hold, then U α , β generates a C 0 ‐semigroup U α , β =( U α , β ( t )) t ≥0 .
- If , , and ( A μ − η )hold, then the C 0 ‐semigroup U α , β =( U α , β ( t )) t ≥0 is contractive provided that .
Proof T α , β is a generator because of , Theorem 4.4]. The points (1), (2), and (3), respectively, follow from , Theorem 5.1], , Theorem 6.2], and , Theorem 6.3].…”