Fixes after review on the consensus PR

EIPS/eip-4844.md

@@ -74,7 +74,7 @@ Compared to full data sharding, this EIP has a reduced cap on the number of thes
 | `Blob` | `Vector[BLSFieldElement, FIELD_ELEMENTS_PER_BLOB]` | |
 | `VersionedHash` | `Bytes32` | |
 | `KZGCommitment` | `Bytes48` | Same as BLS standard "is valid pubkey" check but also allows `0x00..00` for point-at-infinity |
-| `KZGProof` | Bytes48 | Same as for `KZGCommitment` |
+| `KZGProof` | `Bytes48` | Same as for `KZGCommitment` |
 
 ### Helpers
 
@@ -91,7 +91,7 @@ def lincomb(points: List[KZGCommitment], scalars: List[BLSFieldElement]) -> KZGC
     return r
 
 def blob_to_kzg(blob: Blob) -> KZGCommitment:
-    return lincomb(blob, KZG_SETUP_LAGRANGE)
+    return lincomb(KZG_SETUP_LAGRANGE, blob)
 ```
 
 Converts a KZG point into a versioned hash:
@@ -122,24 +122,15 @@ Efficiently evaluates a polynomial in evaluation form using the barycentric form
 ```python
 def bls_modular_inverse(x: BLSFieldElement) -> BLSFieldElement:
     """
-    Compute the modular inverse of x using the eGCD algorithm
+    Compute the modular inverse of x
     i.e. return y such that x * y % BLS_MODULUS == 1 and return 0 for x == 0
     """
-    if x == 0:
-        return 0
-
-    lm, hm = 1, 0
-    low, high = x % BLS_MODULUS, BLS_MODULUS
-    while low > 1:
-        r = high // low
-        nm, new = hm - lm * r, high - low * r
-        lm, low, hm, high = nm, new, lm, low
-    return lm % BLS_MODULUS
+    return pow(x, -1, BLS_MODULUS) if x != 0 else 0
 
 
 def div(x, y):
     """Divide two field elements: `x` by `y`"""
-    return x * inv(y) % MODULUS
+    return x * bls_modular_inverse(y) % BLS_MODULUS
 
 
 def evaluate_polynomial_in_evaluation_form(poly: List[BLSFieldElement], x: BLSFieldElement) -> BLSFieldElement: