#### Follow-up Meeting

Alejandro Gómez-Londoño

5th May 2021

#### Outline

• Current research
• Planned projects

#### Planned projects

A flat reachability-based measure for a verified cost semantics
• A follow-up to the cost semantics project.
• The current size_of measure is quite tricky to reason about.
• Using a flat representation of all reachable objects in the heap, we can more easily talk about changes to it.
• This measure can be implemented in a way that does not break existing proofs.
Composing CakeML programs with choreographies
• Currently each projected endpoint gets its own theorem which assumes all other endpoints are around.
• A stronger guarantee is a single global theorem that talks about all endpoints being projected.
• Possibility of collaboration with ongoing work on new interaction tree semantics for CakeML.
Verified systems using Choreographies and CakeML on seL4
• A case study of a verified concurrent system.
• All components are defined using choreographies.
• Each component is a CakeML program with a proof of correctness.
• The whole system runs on the Sel4 microkernel.
Data-cost on choreography endpoints
• Proof for one or more endpoints that local computations do not run out of memory.