Appendix to “Amenable actions of real and p -adic algebraic groups” by Alain Valette

Key Points

• The aim is to extend the ideas of amenability from group actions to groupoids.
• Analyzed smooth, second countable, locally compact groupoids.
• Utilized Borel Haar systems to investigate amenability.
• Demonstrated equivalence between measurewise amenability and isotropy subgroup amenability.
• Measurewise amenability is equivalent to the amenability of isotropy subgroups for the studied groupoids.