〈a, b | aaba=bb, abbb=b〉

Properties

• Infinite commutative monoid
• Isomorphic to commutative presentation: 〈a, b | 4b=2a+b, a+3b=b, 3a+b=2b〉
• Grothendieck group is ℤ₇

Completion parameters

• Reduction order: left-to-right b/a

Complete rewriting system

1. b⁸ ⇒ b
2. ab ⇒ b⁶
3. ba ⇒ b⁶

Right Cayley graph (truncated)