{
  "handle": "Aggregate",
  "mechanism": "A deterministic function that maps a {{vector}} of inputs to a single Scalar {{value}}. Implements standard statistical operations (Mean, Mode, Median) to compress signal bandwidth. When the caller supplies {{weights}} alongside the vector, the reduction becomes a weighted one. It serves as the computational backbone for consensus mechanisms.",
  "gloss": "Reduce a set to a summary statistic",
  "failure_modes": [
    "Type Mismatch: Input list contains incomparable types (e.g., Integers mixed with Strings).",
    "Empty Set: Attempting to aggregate a list with length 0 (Undefined for Mean/{{mode}}).",
    "Overflow: Sum of inputs exceeds maximum integer size (if strictly typed)."
  ],
  "invariants": [
    "Determinism: F(Input) always yields the same Output.",
    "Yields one scalar {{value}} whatever the input length, including length one."
  ],
  "preconditions": [
    "All elements in list share a comparable type",
    "Input list is non-empty"
  ],
  "postconditions": [
    "Single summary value returned"
  ],
  "parameters": [
    {
      "name": "function",
      "type": "Enum",
      "range": "{Mean, Median, Mode, Sum, Min, Max, Variance, StdDev}",
      "description": "Default: Mean"
    }
  ],
  "_meta": {
    "tier": 1,
    "ring": 0,
    "supersedes": [
      "sema:Aggregate#mh:SHA-256:af54a8a31d6e7ed0c6d7bdfb51935655b0a66d299bddb352dbff9f4a789e7486",
      "sema:Aggregate#mh:SHA-256:4861bd34b2e422951e42b0fd804dab73daa2753ea746c0141927c3e5c6ea8f4b",
      "sema:Aggregate#mh:SHA-256:d1d523ccf371305ebfbd971b5b6630a517bfcb0217ff4639d2db12a01bc181a8"
    ],
    "path": [
      "Infrastructure",
      "Primitives"
    ]
  },
  "sema_id": "sema:Aggregate#mh:SHA-256:2db6858c061515fa2257c96f4a6e4392164e9a118adc6874c69cf2279b877077",
  "sema_ref": "Aggregate#2db6",
  "sema_stub": "2db6",
  "dependencies": {
    "accepts": {
      "vector": "sema:Vector#mh:SHA-256:426835100cd1b60d25e87518ba77200fc7b7ec87b917448e09fc03b1087f6993",
      "weights": "sema:Vector#mh:SHA-256:426835100cd1b60d25e87518ba77200fc7b7ec87b917448e09fc03b1087f6993"
    },
    "references": {
      "mode": "sema:Mode#mh:SHA-256:29d368514a2a815e9790a384c2aec12bd20a30e1ee06288e0aa59fdcffea0800"
    },
    "yields": {
      "value": "sema:Value#mh:SHA-256:37fd75758d04cdd7f57a636ccb5394d463713d60c33b694e37ab71f4a5a896f8"
    }
  },
  "sema_layer": "Infrastructure",
  "sema_category": "Primitives",
  "used_by": {
    "references": {
      "ChunkMerge": "sema:ChunkMerge#mh:SHA-256:a7a32d00372fcda30401ab77dbcb3a3b53fd3c4f013a2c9a5346e8b49ed76285",
      "DriftWatch": "sema:DriftWatch#mh:SHA-256:b696959258eb3c48ce11055634b107451d5a500bc8ba19693db4c30b5f5033bf",
      "PerspectiveEnsemble": "sema:PerspectiveEnsemble#mh:SHA-256:4afd1d6c7abb339c91b3bd94f791e2f57638e9a8c5431757d2c7ae1d6ce8545d",
      "SelfConsistency": "sema:SelfConsistency#mh:SHA-256:4f68cebc4f82197975d6098701b0431bafb1e79792d19cb69a8d9dbad5036b8a",
      "Vote": "sema:Vote#mh:SHA-256:84935dbc846bcd8fe2da01e9e04401f190769e87d0354e00c0986e43e414f300"
    },
    "composes_with": {
      "Parallelize": "sema:Parallelize#mh:SHA-256:c1c795defd6f4f9cab2823cf832ae91f5f0651bef082108bb494047d91be04a1"
    }
  }
}