Sebastian Graf
Sebastian Graf is a programming-language researcher whose work spans compiler analysis and formal program verification. A KIT work on call-arity analysis appeared in 2017; he coauthored lambda-lifting research in 2019 and a GHC coverage checker in 2020. At KIT, he completed a doctorate on functional abstract interpretation in 2024 and coauthored a method for deriving static analyses from a generic interpreter. At Lean FRO, he developed logic for monadic Lean programs in February 2025 and ported Lean's verification-condition generator to SymM in July 2026; Lean also supports AI-authored mathematics. As of October 2026, he is a Research Software Engineer at Lean FRO.
- Works
- 5
- Citations
- 9
- h-index
- 1
Publication numbers from OpenAlex, as of 22 October 2026.
Timeline
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August 2017
Call Arity vs. Demand Analysis
In August 2017, he publishes Call Arity vs. Demand Analysis as a KIT research work.
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2019
Selective lambda lifting
In 2019, he and Simon Peyton Jones publish an optimizing code-generation strategy for functional languages. It uses heuristics to select beneficial lambda lifts and estimates their effect on heap allocation in the Glasgow Haskell Compiler.
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August 2020
Lower Your Guards
In August 2020, he coauthors Lower Your Guards with Simon Peyton Jones and Ryan G. Scott, a compositional checker for Haskell pattern matches. The algorithm reduces complex patterns to guard trees and is implemented in GHC.
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2024
Abstracting Denotational Interpreters
In 2024, he coauthors Abstracting Denotational Interpreters with Simon Peyton Jones and Sven Keidel. The generic interpreter yields dynamic semantics and summary-based static analyses, including type analysis.
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December 2024
A KIT doctorate
In December 2024, he completes a doctorate at KIT with a thesis titled Functional Abstract Interpretation. The thesis presents a more efficient and precise static analysis for Haskell pattern-match coverage and a design pattern for deriving higher-order analyses from a generic interpreter.
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February 2025
Program logic for Lean monads
In February 2025, he works on behalf of Lean FRO on a Floyd/Hoare-style program logic for verifying monadic code in Lean. It is designed to let users define monads and verify programs with shared logic and automation.
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July 2026
Porting vcgen to SymM
In July 2026, he ports Lean's verification-condition generator for monadic programs to SymM, a monadic framework for high-performance software verification. Lean also supports AI-authored mathematics, where AI agents write and review the code.
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As of October 2026
Research Software Engineer
As of October 2026, he is a Research Software Engineer at Lean FRO. He works on a verification condition generator for monadic programs written in Lean.
Career
- NowLean Focused Research OrganizationResearch Software Engineer
Education
- 2024Karlsruhe Institute of TechnologyDoctorate
Most-cited works
Sources and credits
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- Other Publications: Call Arity vs. Demand Analysis
- Other Publications: Selective Lambda Lifting
- Journal Article: Lower Your Guards: A Compositional Pattern-Match Coverage Checker
- Abstracting Denotational Interpreters
- Ph.D. thesis: Functional Abstract Interpretation
- Monadic program logic: Request for feedback | Zulip Chat Archive
- The Lean Theorem Prover: Design, Evolution, and Impact
- fixpt · About
- Team — Lean Lang

