Solution
= Solution
If $\eta_2$ is monic, then $\eta_2(0)\neq\eta_2(1)$. The free algebra $(T2,\mu_2)$ therefore has more than one element, proving the existence of a nontrivial $T$-algebra.
= Solution
If $\eta_2$ is monic, then $\eta_2(0)\neq\eta_2(1)$. The free algebra $(T2,\mu_2)$ therefore has more than one element, proving the existence of a nontrivial $T$-algebra.