SemiBase

A certified basis of 25 identities

This list of identities is a basis, proved in Lean, of 58 semigroups of order six, all of which generate the variety V[4040]. Removing the identities that follow from the others leaves 3 identities (Vampire); the variety page shows the shortest known basis.

Identifier sb-0f13b4b66a49655f in the data of the bases-min seal.

Certified for

The identities

  1. x² ≈ x⁴
  2. x³yx ≈ xyx
  3. x³y² ≈ yxy
  4. x²yx ≈ xyx²
  5. x²yx ≈ yxy²
  6. x²yx² ≈ xyx
  7. x²yxy ≈ yxy
  8. x²y² ≈ xyxy
  9. x²y² ≈ xy²x
  10. x²y² ≈ yx²y
  11. x²y²x ≈ yxy
  12. x²y³ ≈ xyx
  13. xyx ≈ xyx³
  14. xyx ≈ xyxy²
  15. xyx ≈ xy²xy
  16. xyx ≈ xy³x
  17. xyx ≈ yx²y²
  18. xyx ≈ yxyxy
  19. xyx ≈ yxy²x
  20. xyzx ≈ xzyx
  21. x²yzx ≈ yxyzy
  22. x²yzy ≈ xyxzy
  23. x²yzy ≈ xy²zx
  24. x²yzy ≈ xzxy²
  25. x²yzy ≈ yx²zy