leanprover-community/mathlib4
Apr 2026 – Apr 2026
1 Month active
Languages Used
Lean
Technical Skills
Leanformal verificationgraph theory
Tianyi Zhao
PROFILE
Tianyi Zhao
Contributed a graph-theory enhancement to the leanprover-community/mathlib4 repository by introducing predicates for chords and chordless walks in simple graphs. Developed a new module, SimpleGraph/Walk/Chord.lean, which defines Walk.IsChord and Walk.IsChordless to support formal reasoning about the presence or absence of chords in graph walks. This addition extends the Combinatorics/SimpleGraph/Walk toolbox, enabling more expressive and automated proofs in graph theory. The work demonstrated proficiency in Lean, formal verification, and graph theory, and was delivered collaboratively in an open-source environment. No bug fixes were reported during this period, with efforts focused on expanding library capabilities for advanced mathematical proofs.
Overall Statistics
Feature vs Bugs
100%Features
Repository Contributions
1Total
Bugs
0
Commits
1
Features
1
Lines of code
59
Activity Months1
Your Network
315 peopleShared Repositories
315
Work History
April 2026
1 Commits • 1 Features
Apr 1, 2026April 2026: Delivered a graph-theory enhancement for mathlib4 by introducing chords and chordless-walk predicates in simple graphs. Implemented as a new module SimpleGraph/Walk/Chord.lean, adding Walk.IsChord and Walk.IsChordless predicates. This feature extends the Combinatorics/SimpleGraph/Walk toolbox, enabling formal reasoning about chords in walks and facilitating more robust graph-theory proofs. The change is captured in commit 0e1cdf652df62e1905844004bdfcf0e9477cf216 (co-authored by scp020). No major bug fixes were reported this month for this area. Technologies demonstrated include Lean, formal graph theory formalization, and collaborative, open-source development. Business value: enhances library capabilities for advanced graph-theory proofs, improving proof automation and downstream tooling.
1 Commits • 1 Features
Apr 1, 2026April 2026: Delivered a graph-theory enhancement for mathlib4 by introducing chords and chordless-walk predicates in simple graphs. Implemented as a new module SimpleGraph/Walk/Chord.lean, adding Walk.IsChord and Walk.IsChordless predicates. This feature extends the Combinatorics/SimpleGraph/Walk toolbox, enabling formal reasoning about chords in walks and facilitating more robust graph-theory proofs. The change is captured in commit 0e1cdf652df62e1905844004bdfcf0e9477cf216 (co-authored by scp020). No major bug fixes were reported this month for this area. Technologies demonstrated include Lean, formal graph theory formalization, and collaborative, open-source development. Business value: enhances library capabilities for advanced graph-theory proofs, improving proof automation and downstream tooling.
April 2026
Activity
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Quality Metrics
Correctness100.0%
Maintainability100.0%
Architecture100.0%
Performance100.0%
AI Usage20.0%
Skills & Technologies
Programming Languages
Lean
Technical Skills
Leanformal verificationgraph theory
Repositories Contributed To
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