update based on comment

Author: 0x00101010

src/engine/osaka.md

@@ -33,7 +33,7 @@ The fields are encoded as follows:
 - `proofs`: `Array of DATA` - Array of `KZGProof` (48 bytes each, type defined in [EIP-4844](https://eips.ethereum.org/EIPS/eip-4844), semantics defined in [EIP-7594](https://github.com/ethereum/EIPs/blob/master/EIPS/eip-7594.md)).
 - `blobs`: `Array of DATA` - Array of blobs, each blob is `FIELD_ELEMENTS_PER_BLOB * BYTES_PER_FIELD_ELEMENT = 4096 * 32 = 131072` bytes (`DATA`) representing a SSZ-encoded `Blob` as defined in [EIP-4844](https://eips.ethereum.org/EIPS/eip-4844)
 
-`blobs` and `commitments` arrays **MUST** be of same length, `proofs` contains exactly `CELLS_PER_EXT_BLOB` * `len(blobs)` cell proofs.
+`blobs` and `commitments` arrays **MUST** be of same length and `proofs` **MUST** contain exactly `CELLS_PER_EXT_BLOB` * `len(blobs)` cell proofs.
 
 ### BlobAndProofV2
 
@@ -42,7 +42,7 @@ The fields are encoded as follows:
 - `blob`: `DATA` - `FIELD_ELEMENTS_PER_BLOB * BYTES_PER_FIELD_ELEMENT = 4096 * 32 = 131072` bytes (`DATA`) representing a SSZ-encoded `Blob` as defined in [EIP-4844](https://eips.ethereum.org/EIPS/eip-4844).
 - `proofs`: `Array of DATA` - Array of `KZGProof` as defined in [EIP-4844](https://eips.ethereum.org/EIPS/eip-4844), 48 bytes each (`DATA`).
 
-`proofs` contains exactly `CELLS_PER_EXT_BLOB` cell proofs.
+`proofs` **MUST** contain exactly `CELLS_PER_EXT_BLOB` cell proofs.
 
 ## Methods
 
@@ -77,16 +77,15 @@ This method follows the same specification as [`engine_getPayloadV4`](./prague.m
    1. `assert len(blobsBundle.commitments) == len(blobsBundle.blobs)` and
    2. `assert len(blobsBundle.proofs) == len(blobsBundle.blobs) * CELLS_PER_EXT_BLOB` and
    3. `assert verify_cell_kzg_proof_batch(commitments, cell_indices, cells, blobsBundle.proofs)` (see [EIP-7594 consensus-specs](https://github.com/ethereum/consensus-specs/blob/36d80adb44c21c66379c6207a9578f9b1dcc8a2d/specs/fulu/polynomial-commitments-sampling.md#verify_cell_kzg_proof_batch))
-      1. `cell_indices` should be `[0, ..., CELLS_PER_EXT_BLOB, 0, ..., CELLS_PER_EXT_BLOB, ...]`. In python, `list(range(CELLS_PER_EXT_BLOB)) * len(blobsBundle.blobs)`
-      2. `commitments` should list each commitment `CELLS_PER_EXT_BLOB` times, repeating it for every cell. In python, `[blobsBundle.commitments[i] for i in range(len(blobsBundle.blobs)) for _ in range(CELLS_PER_EXT_BLOB)]`
-      3. All of the inputs to `verify_cell_kzg_proof_batch` have the same length, `CELLS_PER_EXT_BLOB * len(blobsBundle.blobs)`
+      1. `commitments` should list each commitment `CELLS_PER_EXT_BLOB` times, repeating it for every cell. In python, `[blobsBundle.commitments[i] for i in range(len(blobsBundle.blobs)) for _ in range(CELLS_PER_EXT_BLOB)]`
+      2. `cell_indices` should be `[0, ..., CELLS_PER_EXT_BLOB, 0, ..., CELLS_PER_EXT_BLOB, ...]`. In python, `list(range(CELLS_PER_EXT_BLOB)) * len(blobsBundle.blobs)`
+      3. `cells` is the list of cells for an extended blob. In python, `[compute_cells(blob) for blob in blobsBundle.blobs]` (see [compute_cells](https://github.com/ethereum/consensus-specs/blob/v1.5.0-beta.3/specs/fulu/polynomial-commitments-sampling.md#compute_cells) in consensus-specs)
+      4. All of the inputs to `verify_cell_kzg_proof_batch` have the same length, `CELLS_PER_EXT_BLOB * len(blobsBundle.blobs)`
 
 ### engine_getBlobsV2
 
 Consensus layer clients **MAY** use this method to fetch blobs from the execution layer blob pool.
 
-*Note*: This is a new optional method introduced after Pectra.
-
 #### Request
 
 * method: `engine_getBlobsV2`