Fix typographical errors

zip-0221.rst

@@ -32,7 +32,7 @@ described in ZIP 200. [#zip-0200]_
   where λ is the security parameter.
 
 *Merkle mountain range (MMR)*
-  A Merkle mountain range (MMR) is binary hash tree that allows for efficient appends of
+  A Merkle mountain range (MMR) is a binary hash tree that allows for efficient appends of
   new leaves without changing the value of existing nodes.
 
 
@@ -128,7 +128,7 @@ algorithm:
              / \   / \    / \   /  \   /  \  \
         0   0   1 3   4  7   8 10  11 15  16 18
 
-The MMR tree allow for efficient incremental set update operations (push, pop, prune). In
+MMR trees allow for efficient incremental set update operations (push, pop, prune). In
 addition, MMR update operations and Merkle proofs for recent additions to the leaf set are
 more efficient than other incremental Merkle tree implementations (e.g. Bitcoin's padded
 leafset, sparse Merkle trees, and Zcash's incremental note commitment trees).
@@ -264,6 +264,7 @@ Each MMR node is defined as follows:
   * ``nLatestTimestamp`` is the header's timestamp
 
 - If the node is an internal or root node
+
   * ``nLatestTimestamp`` is inherited from the right child
 
 - Note that due to timestamp consensus rules, ``nLatestTimestamp`` may be smaller than
@@ -278,6 +279,7 @@ Each MMR node is defined as follows:
   * ``nEarliestTarget`` is the header's ``nBits`` field
 
 - If the node is an internal or root node
+
   * ``nEarliestTarget`` is inherited from the left child
 
 - serialized as ``nBits`` (``uint32``)
@@ -289,6 +291,7 @@ Each MMR node is defined as follows:
   * ``nLatestTarget`` is the header's ``nBits`` field
 
 - If the node is an internal or root node
+
   * ``nLatestTarget`` is inherited from the right child
 
 - serialized as ``nBits`` (uint32)
@@ -339,6 +342,7 @@ Each MMR node is defined as follows:
   * ``nEarliestHeight`` is the header's height
 
 - If the node is an internal or root node
+
   * ``nEarliestHeight`` is inherited from the left child
 
 - serialized as ``CompactSize uint``
@@ -564,7 +568,7 @@ This ZIP introduces a new header version. It is identical to the current v4 head
 [#zcashBlock]_, except for the following changes:
 
 1. The version number is changed to `5`.
-2. ``hashSaplingFinalRoot`` is replaced by ``hashChainHistoryRoot``, as described above.
+2. ``hashFinalSaplingRoot`` is replaced by ``hashChainHistoryRoot``, as described above.
 
 The new block header format is:
 
@@ -657,7 +661,7 @@ the proper serialization and commitment format for the nullifier vector.
   * This commitment serves the same purpose as ``hashFinalSaplingRoot`` in current Sapling
     semantics.
   * However, because the MMR tree commits to blocks ``B_x ... B_(n-1)``, the latest
-    commitment will descrie the final treestate of the previous block, rather than the
+    commitment will describe the final treestate of the previous block, rather than the
     current block.
   * Concretely: block 500 currently commits to the final treestate of block 500 in its
     header. With this ZIP, block 500 will commit to all roots up to block 499, but not the