Evidence row 2201656

What was observed

{
  "endpoints": [
    [
      "x402",
      "https://linear-algebra.x402tookit.com/rank"
    ]
  ],
  "name": "Linear Algebra",
  "owner_address": "0xb531320805c5bed1d46aeadcf4f008fdf172dbda",
  "raw": {
    "accepts": [
      {
        "amount": "20000",
        "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
        "extra": {
          "name": "USD Coin",
          "version": "2"
        },
        "maxTimeoutSeconds": 300,
        "network": "eip155:8453",
        "payTo": "0xb531320805C5BED1D46AEaDcF4F008FDF172DBDa",
        "scheme": "exact"
      },
      {
        "amount": "20000",
        "asset": "EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v",
        "extra": {
          "feePayer": "D6ZhtNQ5nT9ZnTHUbqXZsTx5MH2rPFiBBggX4hY1WePM",
          "transactionVersions": [
            0
          ]
        },
        "maxTimeoutSeconds": 300,
        "network": "solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp",
        "payTo": "DUPiupXtuox38dcGoXUKer5mAydCzmaHjrbQ66qeEm8s",
        "scheme": "exact"
      },
      {
        "amount": "20000",
        "asset": "0x3c499c542cEF5E3811e1192ce70d8cC03d5c3359",
        "extra": {
          "name": "USD Coin",
          "version": "2"
        },
        "maxTimeoutSeconds": 300,
        "network": "eip155:137",
        "payTo": "0xb531320805C5BED1D46AEaDcF4F008FDF172DBDa",
        "scheme": "exact"
      },
      {
        "amount": "20000",
        "asset": "0xaf88d065e77c8cC2239327C5EDb3A432268e5831",
        "extra": {
          "name": "USD Coin",
          "version": "2"
        },
        "maxTimeoutSeconds": 300,
        "network": "eip155:42161",
        "payTo": "0xb531320805C5BED1D46AEaDcF4F008FDF172DBDa",
        "scheme": "exact"
      }
    ],
    "description": "Rank, nullity and reduced row echelon form of a matrix (up to 10x10) with pivot columns.",
    "extensions": {
      "bazaar": {
        "info": {
          "input": {
            "method": "GET",
            "queryParams": {
              "A": "[[1,2,3],[4,5,6],[7,8,9]]"
            },
            "type": "http"
          },
          "output": {
            "example": {
              "asOf": "2026-10-12T00:51:56.246Z",
              "cols": 3,
              "degraded": false,
              "disclaimer": "Screening signal computed from the named public source. Not financial, legal or investment advice; provided as is. Verify at the source before acting.",
              "fullRank": false,
              "leftNullity": 1,
              "notChecked": [
                "rank is numerical: an entry or pivot at most 1e-12 times the largest entry counts as zero, so a matrix that is nearly rank-deficient can be reported full rank and vice versa",
                "a singular-value (SVD) rank, which is more robust for noisy data"
              ],
              "nullity": 1,
              "pivotColumns": [
                0,
                1
              ],
              "rank": 2,
              "reasons": [
                "Gauss-Jordan elimination with partial pivoting; the rank is the number of pivots.",
                "Nullity is columns minus rank (the dimension of the null space)."
              ],
              "rows": 3,
              "rref": [
                [
                  1,
                  0
                ],
                [
                  0,
                  1
                ]
              ],
              "source": "computed locally",
              "summary": "Rank 2 of a 3x3 matrix (rank deficient); nullity 1.",
              "verdict": "RANK_DEFICIENT"
            },
            "type": "json"
          }
        },
        "schema": {
          "$schema": "https://json-schema.org/draft/2020-12/schema",
          "properties": {
            "input": {
              "additionalProperties": false,
              "properties": {
                "method": {
                  "enum": [
                    "GET"
                  ],
                  "type": "string"
                },
                "queryParams": {
                  "properties": {
                    "A": {
                      "description": "Matrix, JSON like [[1,2,3],[4,5,6],[7,8,9]] or 1,2,3;4,5,6;7,8,9 (max 10x10)",
                      "type": "string"
                    }
                  },
                  "required": [
                    "A"
                  ],
                  "type": "object"
                },
                "type": {
                  "const": "http",
                  "type": "string"
                }
              },
              "required": [
                "type",
                "method"
              ],
              "type": "object"
            },
            "output": {
              "properties": {
                "example": {
                  "properties": {
                    "asOf": {
                      "type": [
                        "null",
                        "string"
                      ]
                    },
                    "cols": {
                      "type": [
                        "null",
                        "number"
                      ]
                    },
                    "degraded": {
                      "type": [
                        "boolean",
                        "null"
                      ]
                    },
                    "disclaimer": {
                      "type": [
                        "null",
                        "string"
                      ]
                    },
                    "fullRank": {
                      "type": [
                        "boolean",
                        "null"
                      ]
                    },
                    "leftNullity": {
                      "type": [
                        "null",
                        "number"
                      ]
                    },
                    "notChecked": {
                      "items": {
                        "type": "string"
                      },
                      "type": [
                        "array",
                        "null"
                      ]
                    },
                    "nullity": {
                      "type": [
                        "null",
                        "number"
                      ]
                    },
                    "pivotColumns": {
                      "items": {
                        "type": "number"
                      },
                      "type": [
                        "array",
                        "null"
                      ]
                    },
                    "rank": {
                      "type": [
                        "null",
                        "number"
                      ]
                    },
                    "reasons": {
                      "items": {
                        "type": "string"
                      },
                      "type": [
                        "array",
                        "null"
                      ]
                    },
                    "rows": {
                      "type": [
                        "null",
                        "number"
                      ]
                    },
                    "rref": {
                      "items": {
                        "items": {
                          "type": "number"
                        },
                        "type": "array"
                      },
                      "type": [
                        "array",
                        "null"
                      ]
                    },
                    "source": {
                      "type": [
                        "null",
                        "string"
                      ]
                    },
                    "summary": {
                      "type": [
                        "null",
                        "string"
                      ]
                    },
                    "verdict": {
                      "type": [
                        "null",
                        "string"
                      ]
                    }
                  },
                  "type": "object"
                },
                "type": {
                  "type": "string"
                }
              },
              "required": [
                "type"
              ],
              "type": "object"
            }
          },
          "required": [
            "input"
          ],
          "type": "object"
        }
      }
    },
    "lastUpdated": "2026-11-01T23:34:10.411Z",
    "quality": {
      "l30DaysTotalCalls": 2,
      "l30DaysUniquePayers": 2,
      "lastCalledAt": "2026-11-01T23:34:10.249Z"
    },
    "resource": "https://linear-algebra.x402tookit.com/rank",
    "serviceName": "Linear Algebra",
    "tags": [
      "rank",
      "rref",
      "nullity",
      "matrix"
    ],
    "type": "http",
    "x402Version": 2
  },
  "source": "x402_bazaar",
  "summary": "Rank, nullity and reduced row echelon form of a matrix (up to 10x10) with pivot columns."
}

What the leaf hashes

{"body":"2ec36d54c366625ac46e520086bc79f62d1de255933e7283ca021c2f0b46d14c","id":2201656,"kind":"listing","method":"sync.x402_bazaar/1","observed_us":1793646807759144,"prev":null,"subject":"x402_bazaar:https://linear-algebra.x402tookit.com/rank","subject_kind":"source_record"}

Proof

Fold these into the leaf in order, hashing each sorted pair with keccak256, to reach the root of 2026-11-02 (444186 rows).

1. 0xda36ec27b69b6002365acc28d32b0cfb955bb5d73262840b63cd319238d65a15
2. 0x1727c9c12609ecc63baa2ce03ce7e6e281a2d75dd2bb89d2c1a615723f869a28
3. 0x7a4a50d8bc1053e1446bd8da6f3d780f043edcb986f95fa5686c16161e3ca5dd
4. 0x63b0dc1d7d2b7d06948a34c9fec93f395cf038876f28acd85b60e8c5a51c19aa
5. 0x4f02815059ea1ba4f041b9bb6e35d649196b017fa3dfb9f6e6e4cc3e610eee7e
6. 0xebc6768f56418812a09fe06c3f3bc55f9a4455b23201daf7436f37997eab65b5
7. 0xcd7c5987b4854179fd1ce4b2d4813a16750f1d180998f1049991fc0ec0d3988e
8. 0x47e9b4434d1da6957c416ce1ef88f49484c17fae4298c7b62fb234af176f431c
9. 0x974b176adcde056e4e5dda6acfbea852408fdced8b3774ddc04b1bfd4a3456e4
10. 0x840e23646b1a499d612012a05b61baaa10049072216cf49682a05742593342dc
11. 0xfe01d075aece76c51e7ce31afbe5dc6b6ec09317ec86567954b888ae558a37e1
12. 0xc8b8fbd944f03f1fef9180edc64fe8b61cdae8db900d73504261d8c04a5cdcba
13. 0xf501fcee968477faaca9a060259336a60c82a32ca56ab2da724f950f415e8b62
14. 0xaed7c1080b4ff0b1fc4f851df0f2b8b4ef86b106015aa3aaf8da39a641c41a3d
15. 0xa370e8e015a32408a8112e54e5f40a8a65e871bd52bbc6f25fbd1139f2ba5b11
16. 0x7ddefa7d79e7640c3fed21ee4472689415182c41a0258ab04a81d60495f4c40a
17. 0xdb8bd933619a267f9790faac9839143d202be46af284371cc369cdf683f897ba
18. 0x98cbbf2c68ab4c0b4db782aeb88bea1f30b02178cf8b5d3d24a931d19492ea6d
19. 0x252cce55f1a3d5391c16f82d7f62494429a5f69b03486d4cfcfb7b2c96d6c884

Day root

0x78fecaabbe319e56f5c4b80fc02e2052e198ad24781da8832a475ff65f2002d1

Chained

0xdc35957db5d1371ca382b9152878ffece28ec7c5cb4f98fd71ddb367f8b999b2

Published

On Arc Testnet, block 70432815: 0x56b814612eb2e3e544153df3e91e1f7199106d1e430c7d8c6b653feeb9ebe9af