diff --git a/reference/nim/proof_input/proof_input.nimble b/reference/nim/proof_input/proof_input.nimble
index cf8ac91..d6a7d6b 100644
--- a/reference/nim/proof_input/proof_input.nimble
+++ b/reference/nim/proof_input/proof_input.nimble
@@ -10,5 +10,5 @@ bin           = @["cli"]
 requires "nim >= 1.6.0"
 requires "https://github.com/mratsim/constantine#ab6fa6ae1bbbd1b10071a92ec209b381b5d82511"
 requires "https://github.com/codex-storage/nim-poseidon2#8a54c69032a741160bbc097d009e45a8b5e4d718"
-requires "https://github.com/codex-storage/nim-goldilocks-hash#0d12b1429345c3f359df47171332e8966dc94ed3"
-#requires "../../../../nim-goldilocks-hash/"
+requires "https://github.com/codex-storage/nim-goldilocks-hash#bd5b805b80b6005a3e5de412dec15783284d205d"
+#requires "goldilocks_hash == 0.0.1"
diff --git a/reference/nim/proof_input/src/json/bn254.nim b/reference/nim/proof_input/src/json/bn254.nim
index 997b7e8..34b7c35 100644
--- a/reference/nim/proof_input/src/json/bn254.nim
+++ b/reference/nim/proof_input/src/json/bn254.nim
@@ -17,7 +17,7 @@ import shared
 #-------------------------------------------------------------------------------
 
 proc writeFieldElems(h: Stream, prefix: string, xs: seq[F]) = 
-  writeList[F]( h, prefix, xs, writeF )
+  writeList[F]( h, prefix, xs, writeLnF )
 
 #-------------------------------------------------------------------------------
 
diff --git a/reference/nim/proof_input/src/json/goldilocks.nim b/reference/nim/proof_input/src/json/goldilocks.nim
index b76749f..2784789 100644
--- a/reference/nim/proof_input/src/json/goldilocks.nim
+++ b/reference/nim/proof_input/src/json/goldilocks.nim
@@ -20,16 +20,23 @@ func bytesToFieldElements( bytes: openArray[byte] ): seq[F] =
   let digests = padAndDecodeBytesToDigest62(bytes)
   return digestSeqToFeltSeq(digests)
 
+func bytesToFieldElementsMat( bytes: openArray[byte] ): seq[seq[F]] = 
+  let digests = padAndDecodeBytesToDigest62(bytes)
+  return digestSeqToFeltSeqSeq(digests)
+
 #-------------------------------------------------------------------------------
 
 proc writeFieldElems(h: Stream, prefix: string, xs: seq[F]) = 
-  writeList[F]( h, prefix, xs, writeF )
+  writeList[F]( h, prefix, xs, writeLnF )
+
+proc writeFieldElemsMat(h: Stream, prefix: string, xs: seq[seq[F]]) = 
+  writeListList[F]( h, prefix, xs, writeF )
 
 #-------------------------------------------------------------------------------
 
 proc writeSingleCellData(h: Stream, prefix:string , cell: Cell) = 
-  let flds : seq[F] = bytesToFieldElements(cell)    # cell.elements(F).toSeq()
-  writeFieldElems(h, prefix, flds)
+  let flds : seq[seq[F]] = bytesToFieldElementsMat(cell)   
+  writeFieldElemsMat(h, prefix, flds)
 
 proc writeAllCellData(h: Stream, cells: seq[Cell]) = 
   writeList(h, "    ", cells, writeSingleCellData )
@@ -37,8 +44,8 @@ proc writeAllCellData(h: Stream, cells: seq[Cell]) =
 #-------------------------------------------------------------------------------
 
 proc writeSingleMerklePath(h: Stream, prefix: string, path: MerkleProof[Digest]) = 
-  let flds : seq[F] = digestSeqToFeltSeq( path.merklePath )
-  writeFieldElems(h, prefix, flds)
+  let flds : seq[seq[F]] = digestSeqToFeltSeqSeq( path.merklePath )
+  writeFieldElemsMat(h, prefix, flds)
 
 proc writeAllMerklePaths(h: Stream, paths: seq[MerkleProof[Digest]]) = 
   writeList(h, "    ", paths, writeSingleMerklePath )
diff --git a/reference/nim/proof_input/src/json/shared.nim b/reference/nim/proof_input/src/json/shared.nim
index 1fb0217..dc72af6 100644
--- a/reference/nim/proof_input/src/json/shared.nim
+++ b/reference/nim/proof_input/src/json/shared.nim
@@ -24,4 +24,27 @@ proc writeList*[T](h: Stream, prefix: string, xs: seq[T], writeFun: WriteFun[T])
       writeFun(h, indent & ", ", xs[i])
   h.writeLine( indent & "]" )
 
+#---------------------------------------
+
+proc writeListList*[T](h: Stream, prefix: string, xs: seq[seq[T]], writeFun: WriteFun[T]) = 
+  let n = xs.len
+  let indent = mkIndent(prefix)
+  for i in 0..<n:
+
+    if i==0:
+      h.write( prefix & "[ ")
+    else:
+      h.write( indent & ", ")
+
+    let ys = xs[i]
+    let m = ys.len
+    for j in 0..<m:
+      if j==0:
+        writeFun(h, ""   , ys[j])
+      else:
+        writeFun(h, " , ", ys[j])
+
+    h.write("\n")
+  h.writeLine( indent & "]" )
+
 #-------------------------------------------------------------------------------
diff --git a/reference/nim/proof_input/src/types/bn254.nim b/reference/nim/proof_input/src/types/bn254.nim
index fac932a..f7bba1e 100644
--- a/reference/nim/proof_input/src/types/bn254.nim
+++ b/reference/nim/proof_input/src/types/bn254.nim
@@ -36,9 +36,12 @@ func toQuotedDecimalF*(x: F): string =
   let s : string = toDecimalF(x)
   return ("\"" & s & "\"")
 
-proc writeF*(h: Stream, prefix: string, x: F) =
+proc writeLnF*(h: Stream, prefix: string, x: F) =
   h.writeLine(prefix & toQuotedDecimalF(x))
 
+proc writeF*(h: Stream, prefix: string, x: F) =
+  h.write(prefix & toQuotedDecimalF(x))
+
 #-------------------------------------------------------------------------------
 
 func extractLowBits[n: static int]( A: BigInt[n], k: int): uint64 = 
diff --git a/reference/nim/proof_input/src/types/goldilocks.nim b/reference/nim/proof_input/src/types/goldilocks.nim
index 176ad0c..1bbfefc 100644
--- a/reference/nim/proof_input/src/types/goldilocks.nim
+++ b/reference/nim/proof_input/src/types/goldilocks.nim
@@ -23,9 +23,12 @@ func toQuotedDecimalF*(x: F): string =
   let s : string = toDecimalF(x)
   return ("\"" & s & "\"")
 
-proc writeF*(h: Stream, prefix: string, x: F) =
+proc writeLnF*(h: Stream, prefix: string, x: F) =
   h.writeLine(prefix & toQuotedDecimalF(x))
 
+proc writeF*(h: Stream, prefix: string, x: F) =
+  h.write(prefix & toQuotedDecimalF(x))
+
 #-------------------------------------------------------------------------------
 
 func extractLowBits*(fld: F, k: int): uint64 = 
@@ -38,7 +41,9 @@ func extractLowBits*(fld: F, k: int): uint64 =
 
 func digestToJsonString*( d: Digest ): string = 
   let xs: F4 = fromDigest(d) 
-  return "[ " & toDecimalF(xs[0]) & ", " &
-                toDecimalF(xs[1]) & ", " &
-                toDecimalF(xs[2]) & ", " &
-                toDecimalF(xs[3]) & " ]"
\ No newline at end of file
+  return "[ " & toQuotedDecimalF(xs[0]) & ", " &
+                toQuotedDecimalF(xs[1]) & ", " &
+                toQuotedDecimalF(xs[2]) & ", " &
+                toQuotedDecimalF(xs[3]) & " ]"
+
+#-------------------------------------------------------------------------------