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Programming language

Lean 4

Lean 4 is an open-source functional programming language and interactive proof assistant used to formally verify software and mathematical proofs.

Known aliases

  • Lean
  • Lean4

Current stories

buildConfirmed8 publishers

OpenAI ships a Lean build that checks its Navier-Stokes proof against its own definitions

OpenAI's 165-page proof ships with a Lean 4 formalization anyone can download and build, which settles whether the argument follows from its own definitions and leaves whether those definitions state the Clay problem to human readers.

Perspective Coverage

8 publishers
Builder
Builder 41%
Operator
Operator 30%
Investor
Investor 29%

Reality

Evidence50
Adoption
Not scored
Hype gap+40
Incentives70
Confidence60
productConfirmed2 publishers

OpenAI readies hundreds of AI math results for GitHub despite mathematicians' request for papers going unheeded

OpenAI plans to post hundreds of AI-generated math results on GitHub on Tuesday, people familiar with the plans told WIRED. The mathematicians it consulted in August asked for papers they could absorb and use, so a bulk upload leaves that work to every reader.

Reality

Evidence45
Adoption
Not scored
Hype gap+55
Incentives70
Confidence50
buildOne report1 publisher

Claude agents' 13-million-line Fermat proof shrinks human review to one statement and three axioms

Anthropic published a 13-million-line Lean 4 proof of Fermat's Last Theorem that dozens of Claude agents wrote in 11 days. For teams weighing agents on correctness-critical code, the kernel checks every step, so what humans still review is the statement being proved.

Publishers:dev.to

Reality

Evidence62
Adoption
Not scored
Hype gap+20
Incentives55
Confidence60
buildOne report1 publisher

MathCode's bet is that proofs should accumulate, not evaporate

The Math-AI project turns plain-language mathematics into Lean 4 theorems, then files whatever compiles into a reusable library. The architecture is the claim, not the benchmark.

Publishers:runtimewire.com

Reality

Evidence40
Adoption
Not scored
Hype gap+14
Incentives36
Confidence44