[{"data":1,"prerenderedAt":4},["ShallowReactive",2],{"0IHIPxAfpl":3},"# Strong Robertson conjecture for split-off minors\n\nA Lean 4 formalization of the strong Robertson conjecture for split-off\nminors. The project is pinned to Lean **4.32.1** and uses Mathlib **v4.32.1**\nas a Git submodule.\n\n## Prerequisites\n\n- Git\n- [VS Code](https://code.visualstudio.com/) with the official\n  [Lean 4 extension](https://marketplace.visualstudio.com/items?itemName=leanprover.lean4)\n- `elan`, the Lean toolchain manager\n\nDo not install `lean` or `lake` separately. `elan` reads `lean-toolchain` in\nthis repository and installs the exact Lean version automatically.\n\n## Install on macOS\n\n1. Open Terminal and ensure the Xcode Command Line Tools (including Git) are\n   installed:\n\n   ```sh\n   git --version\n   ```\n\n   If macOS prompts you to install the tools, accept the prompt.\n\n2. Install `elan`:\n\n   ```sh\n   curl https://elan.lean-lang.org/elan-init.sh -sSf | sh\n   source \"$HOME/.elan/env\"\n   ```\n\n3. Install VS Code, then install the official Lean extension. If you use\n   Homebrew, both can be installed with:\n\n   ```sh\n   brew install --cask visual-studio-code\n   code --install-extension leanprover.lean4\n   ```\n\nThe same Lean binaries support both Apple Silicon and Intel Macs.\n\n## Install on Windows\n\n1. Install [Git for Windows](https://git-scm.com/download/win) and\n   [VS Code](https://code.visualstudio.com/). In the installers, enable the\n   option to add each program to `PATH`, then open a new PowerShell window.\n\n2. Download and run the `elan` installer:\n\n   ```powershell\n   curl.exe -O --location https://elan.lean-lang.org/elan-init.ps1\n   powershell -ExecutionPolicy Bypass -File .\\elan-init.ps1\n   Remove-Item .\\elan-init.ps1\n   ```\n\n   Choose the default installation when prompted, then close and reopen\n   PowerShell.\n\n3. In VS Code, open Extensions (`Ctrl+Shift+X`) and install **Lean 4** by\n   `leanprover`, or run:\n\n   ```powershell\n   code --install-extension leanprover.lean4\n   ```\n\nNative Windows is supported; WSL is not required.\n\n## Clone and build\n\nClone with the Mathlib submodule:\n\n```sh\ngit clone --recurse-submodules \u003Crepository-url>\ncd strong-robertson-conjecture-for-split-off-minors\n```\n\nIf the repository was already cloned without submodules, run:\n\n```sh\ngit submodule update --init --recursive\n```\n\nCheck the pinned toolchain, download Mathlib's precompiled cache, and build:\n\n```sh\nlean --version\nlake exe cache get\nlake build\n```\n\nThe first command may take a few minutes while `elan` downloads Lean 4.32.1.\nThe cache command avoids compiling all of Mathlib from source. Open the\nrepository root in VS Code (`code .`) so the Lean extension can find\n`lean-toolchain` and `lakefile.toml`.\n\n## Project layout\n\n- `StrongRobertson/` — formalization source files\n- `StrongRobertson.lean` — root library import\n- `mathlib/` — pinned Mathlib Git submodule\n- `lean-toolchain` — pinned Lean compiler version\n- `lakefile.toml` — Lake package configuration\n\n## Updating the pinned dependency\n\nLean and Mathlib versions must stay compatible. To update, check out a matching\nMathlib release inside the submodule, update `lean-toolchain` to the version in\n`mathlib/lean-toolchain`, regenerate the Lake manifest, and rebuild. Commit both\nthe changed submodule pointer and the toolchain/configuration files.\n\nFor current installation guidance, see the\n[official Lean installation page](https://lean-lang.org/install/).\n",1789154851631]