Abstract: Critical software components often display effects such as randomization,
nondeterminism, concurrency, and exceptions. Complex combinations of effects show up
in distributed systems, security, and privacy applications where correctness is crucial, but
mixtures of effects also make testing and informal reasoning difficult or impossible. While
powerful formal methods exist for reasoning about individual effects, those semantic
foundations do not provide a unified account of how such effects interact. As a result,
verification techniques are highly specialized and difficult to compose.
In this talk, I present Outcome Logic, a logical foundation that captures diverse program
behaviors via a common notion of outcomes. Outcome Logic enables reusable reasoning
principles across deterministic, nondeterministic, and probabilistic settings, and allows
multiple effects to be composed on top of the base logic. I will show how the extensible
approach allows Outcome Logic to support new types of reasoning in domains such as
verification of randomized distributed systems and principled bug-finding techniques.
Bio: Noam is a final year PhD Candidate at Cornell University in the area of Programming
Languages and Formal Methods, advised by Alexandra Silva. Before coming to Cornell, he
was a staff software engineer in the Facebook Programming Languages and Runtimes
team, where he worked on unique projects including using dependently typed Haskell in
production and formally verifying concurrent algorithms for an OS microkernel.
Noam's current research focuses on logical foundations for reasoning about programs that
branch into different outcomes, which provide a unifying perspective for reasoning about a
wide variety of effects including nondeterminism, nontermination, randomization,
concurrency, and exceptions. The resulting Outcome Logic, has applications including
unifying the theories of correctness and incorrectness and verification of concurrent
randomized algorithms. Noam's research is supported in part by the NSF and he was
recently recognized with the 2024 ACM SIGPLAN John Vlissides Award for applied software
research and a distinguished paper award at POPL 2026