〈a, b | aa=a, babbbab=a〉

Properties

• Infinite commutative monoid
• Isomorphic to commutative presentation: 〈a, b | 2b=b, 5a+b=b〉
• Grothendieck group is ℤ₅

Completion parameters

• Reduction order: left-to-right ab

Complete rewriting system

1. a² ⇒ a
2. ba ⇒ ab
3. ab⁵ ⇒ a

Right Cayley graph (truncated)