{
  "version": 1,
  "language": "en",
  "title": "τ₀-WM: candidate tests before execution",
  "description": "VAM makes candidate action chunks, and ACVS predicts outcomes for ranking or optional changes. The selected chunk runs before the system receives fresh observations. The search does not change weights, and prediction cannot certify real contact.",
  "caption": "The author made this test-time mechanism diagram. ACVS predicts outcomes for VAM proposals. Selection or changes occur before execution. The search changes candidate chunks and does not change model weights. Predicted success does not certify real contact. The decisions and playback timing are examples.",
  "alt": "Search flow makes action-chunk proposals and predicts outcomes, with optional changes before execution and fresh observation.",
  "sources": [
    "https://arxiv.org/html/2606.01027v2"
  ],
  "limitations": [
    "The execution is an example. Playback duration is not measured runtime.",
    "This diagram gives no invented score values, training-mixture percentages or real-robot success data."
  ],
  "targets": {
    "observe": {
      "id": "mechanism-observe",
      "kind": "node",
      "label": "Read state"
    },
    "propose": {
      "id": "mechanism-propose",
      "kind": "node",
      "label": "Proposal"
    },
    "forecast": {
      "id": "mechanism-forecast",
      "kind": "node",
      "label": "Predict"
    },
    "select": {
      "id": "mechanism-select",
      "kind": "node",
      "label": "Select"
    },
    "act": {
      "id": "mechanism-act",
      "kind": "node",
      "label": "Execute"
    },
    "observation": {
      "id": "mechanism-observation",
      "kind": "edge",
      "label": "Supply state"
    },
    "candidates": {
      "id": "mechanism-candidates",
      "kind": "edge",
      "label": "Make chunk proposals"
    },
    "outcomes": {
      "id": "mechanism-outcomes",
      "kind": "edge",
      "label": "Predict outcomes"
    },
    "execute": {
      "id": "mechanism-execute",
      "kind": "edge",
      "label": "Execute the chunk"
    },
    "revise": {
      "id": "mechanism-revise",
      "kind": "edge",
      "label": "Change chunks"
    },
    "fresh-observation": {
      "id": "mechanism-fresh-observation",
      "kind": "edge",
      "label": "Read state again"
    }
  },
  "stateLabels": {
    "stage": "Stage",
    "artifact": "Output",
    "weights": "Model weights",
    "candidate": "Candidate state"
  },
  "scenarios": [
    {
      "id": "select-once",
      "title": "Select a candidate",
      "description": "Select a candidate.",
      "initial": {
        "stage": "Available",
        "artifact": "Current observation",
        "weights": "Fixed weights",
        "candidate": "No proposal"
      },
      "unselected": [
        "revise"
      ],
      "steps": [
        {
          "title": "Read the observation",
          "description": "Read the observation.",
          "duration": 3000,
          "active": [
            "observe"
          ],
          "paths": [],
          "state": {
            "stage": "Observation",
            "artifact": "Current robot observations",
            "weights": "Fixed weights",
            "candidate": "No proposal"
          }
        },
        {
          "title": "Make candidate chunk proposals",
          "description": "Make candidate chunk proposals.",
          "duration": 3000,
          "active": [
            "propose"
          ],
          "paths": [
            "observation"
          ],
          "state": {
            "stage": "Proposal",
            "artifact": "Candidate action chunks from VAM",
            "weights": "Fixed weights",
            "candidate": "Initial proposals"
          }
        },
        {
          "title": "Predict candidate outcomes",
          "description": "Predict candidate outcomes.",
          "duration": 3000,
          "active": [
            "forecast"
          ],
          "paths": [
            "candidates"
          ],
          "state": {
            "stage": "Prediction",
            "artifact": "Action-conditioned video predictions",
            "weights": "Fixed weights",
            "candidate": "Initial proposals"
          }
        },
        {
          "title": "Rank predicted futures",
          "description": "Rank predicted futures.",
          "duration": 3000,
          "active": [
            "select"
          ],
          "paths": [
            "outcomes"
          ],
          "state": {
            "stage": "Ranking",
            "artifact": "Predicted outcomes for candidate selection or changes",
            "weights": "Fixed weights",
            "candidate": "Initial proposals"
          }
        },
        {
          "title": "Execute the selected chunk",
          "description": "Execute the selected chunk.",
          "duration": 3000,
          "active": [
            "act"
          ],
          "paths": [
            "execute"
          ],
          "state": {
            "stage": "Execution",
            "artifact": "The system sends the selected action chunk to the physical backend.",
            "weights": "Fixed weights",
            "candidate": "Initial proposals"
          }
        },
        {
          "title": "Get a fresh observation",
          "description": "Get a fresh observation.",
          "duration": 3000,
          "active": [
            "observe"
          ],
          "paths": [
            "fresh-observation"
          ],
          "state": {
            "stage": "Next observation",
            "artifact": "Observed outcomes. Prediction gives no contact guarantee.",
            "weights": "Fixed weights",
            "candidate": "Initial proposals"
          }
        }
      ]
    },
    {
      "id": "revise-before-execution",
      "title": "Changes before execution",
      "description": "Changes before execution",
      "initial": {
        "stage": "Available",
        "artifact": "Current observation",
        "weights": "Fixed weights",
        "candidate": "No proposal"
      },
      "unselected": [],
      "steps": [
        {
          "title": "Read the observation",
          "description": "Read the observation.",
          "duration": 3000,
          "active": [
            "observe"
          ],
          "paths": [],
          "state": {
            "stage": "Observation",
            "artifact": "Current robot observations",
            "weights": "Fixed weights",
            "candidate": "No proposal"
          }
        },
        {
          "title": "Make candidate chunk proposals",
          "description": "Make candidate chunk proposals.",
          "duration": 3000,
          "active": [
            "propose"
          ],
          "paths": [
            "observation"
          ],
          "state": {
            "stage": "Proposal",
            "artifact": "Candidate action chunks from VAM",
            "weights": "Fixed weights",
            "candidate": "Initial proposals"
          }
        },
        {
          "title": "Predict candidate outcomes",
          "description": "Predict candidate outcomes.",
          "duration": 3000,
          "active": [
            "forecast"
          ],
          "paths": [
            "candidates"
          ],
          "state": {
            "stage": "Prediction",
            "artifact": "Action-conditioned video predictions",
            "weights": "Fixed weights",
            "candidate": "Initial proposals"
          }
        },
        {
          "title": "Rank predicted futures",
          "description": "Rank predicted futures.",
          "duration": 3000,
          "active": [
            "select"
          ],
          "paths": [
            "outcomes"
          ],
          "state": {
            "stage": "Ranking",
            "artifact": "Predicted outcomes for candidate selection or changes",
            "weights": "Fixed weights",
            "candidate": "Initial proposals"
          }
        },
        {
          "title": "Change candidate motion",
          "description": "Change candidate motion.",
          "duration": 3000,
          "active": [
            "propose"
          ],
          "paths": [
            "revise"
          ],
          "state": {
            "stage": "Candidate revision",
            "artifact": "Updated candidate action chunks",
            "weights": "Fixed weights",
            "candidate": "Changed proposals"
          }
        },
        {
          "title": "Predict outcomes for changed candidates",
          "description": "Predict outcomes for changed candidates.",
          "duration": 3000,
          "active": [
            "forecast"
          ],
          "paths": [
            "candidates"
          ],
          "state": {
            "stage": "Prediction",
            "artifact": "Predictions for changed candidate chunks",
            "weights": "Fixed weights",
            "candidate": "Changed proposals"
          }
        },
        {
          "title": "Select from the changed proposals",
          "description": "Select from the changed proposals.",
          "duration": 3000,
          "active": [
            "select"
          ],
          "paths": [
            "outcomes"
          ],
          "state": {
            "stage": "Selection",
            "artifact": "Selected action chunk from changed proposals",
            "weights": "Fixed weights",
            "candidate": "Changed proposals"
          }
        },
        {
          "title": "Execute the selected chunk",
          "description": "Execute the selected chunk.",
          "duration": 3000,
          "active": [
            "act"
          ],
          "paths": [
            "execute"
          ],
          "state": {
            "stage": "Execution",
            "artifact": "The system sends the selected action chunk to the physical backend.",
            "weights": "Fixed weights",
            "candidate": "Changed proposals"
          }
        },
        {
          "title": "Get a fresh observation",
          "description": "Get a fresh observation.",
          "duration": 3000,
          "active": [
            "observe"
          ],
          "paths": [
            "fresh-observation"
          ],
          "state": {
            "stage": "Next observation",
            "artifact": "Observed outcomes. Prediction gives no contact guarantee.",
            "weights": "Fixed weights",
            "candidate": "Changed proposals"
          }
        }
      ]
    }
  ]
}