Ante's Borrow Checker Allows Safe Cyclic Mutability Without Runtime Cost

Borrow Checking Zero-Cost Cyclic Mutability

Ante, a low-level functional language with ownership semantics, redesigns its borrow checker to permit shared mutability that Rust rejects. By replacing lifetimes with "places" and marking unstable references, it statically allows patterns like mutating one vector element while holding a reference to another, and even safe cyclic data structures—all without runtime overhead. The design also simplifies interop and reduces borrow-checker errors.