graph TB
    subgraph Standards
        std1["IRIG 106-17\nChapter 10"]
        std2["RCC 123-20\nProgrammer's Handbook"]
    end

    subgraph "L1 — 37 Requirements"
        l1["What the crate SHALL do\nTraced to standard sections\nL1-RTC, L1-ABS, L1-CSDW,\nL1-BCD, L1-SEC, L1-IPT,\nL1-COR, L1-ERR, L1-API"]
    end

    subgraph "L2 — 78 Requirements"
        l2["Testable functional behaviors\nFunction signatures, enums, invariants\nEach traces to exactly one L1"]
    end

    subgraph "L3 — 65 Specifications"
        l3["Struct layouts, algorithms, constants\nMaps directly to source files\nModule map, byte offsets, formulas"]
    end

    subgraph Implementation
        code["Source Code\n8 modules, ~1500 lines Rust"]
        tests["124 Tests\n104 unit + 10 integration\n+ 10 property-based\nEach test traces to L3"]
    end

    std1 --> l1
    std2 --> l1
    l1 --> l2
    l2 --> l3
    l3 --> code
    l3 --> tests
