2 problems

Let $M=\operatorname{Mon}\langle A\mid w_i=1\ (1\leq i\leq p)\rangle$ be a finitely presented special monoid. A monoid has deterministic context-free word problem when its word pro…

Let $M$ be a finitely presented special monoid, generated by $A$, with virtually free group of units. For inputs $u,v\in A^*$, write $n=|u|+|v|$. Quadratic-time word problem conjec…