Let p and q be odd primes and let m and n be positive integers. Prove that U(p^m) + U(a^n) is not cyclic.
(+ is the external direct product (+ with a circle around it))
Let p and q be odd primes and let m and n be positive integers. Prove that U(p^m) + U(a^n) is not cyclic.
(+ is the external direct product (+ with a circle around it))
I think you mean to say . Since are odd it means divides both . And therefore . Thus, their product cannot be cyclic.