Don't use 'X' to abbreviate 'extended', since it is ambiguous with 'expanded'.

zip-0032.rst

@@ -146,9 +146,9 @@ is the normal Sapling full viewing key, *dk* is the same diversifier key as abov
 Helper functions
 ----------------
 
-Define EncodeXSKParts(*ask*, *nsk*, *ovk*, *dk*) := I2LEOSP\ :sub:`256`\ (*ask*) || I2LEOSP\ :sub:`256`\ (*nsk*) || *ovk* || *dk*.
+Define EncodeExtSKParts(*ask*, *nsk*, *ovk*, *dk*) := I2LEOSP\ :sub:`256`\ (*ask*) || I2LEOSP\ :sub:`256`\ (*nsk*) || *ovk* || *dk*.
 
-Define EncodeXFVKParts(*ak*, *nk*, *ovk*, *dk*) := LEBS2OSP\ :sub:`256`\ (repr\ :sub:`𝕁`\ (*ak*)) || LEBS2OSP\ :sub:`256`\ (repr\ :sub:`𝕁`\ (*nk*)) || *ovk* || *dk*.
+Define EncodeExtFVKParts(*ak*, *nk*, *ovk*, *dk*) := LEBS2OSP\ :sub:`256`\ (repr\ :sub:`𝕁`\ (*ak*)) || LEBS2OSP\ :sub:`256`\ (repr\ :sub:`𝕁`\ (*nk*)) || *ovk* || *dk*.
 
 Master key generation
 ---------------------
@@ -181,8 +181,8 @@ CDKsk((*ask*\ :sub:`par`\ , *nsk*\ :sub:`par`\ , *ovk*\ :sub:`par`\ , *dk*\ :sub
 
 - Check whether *i* ≥ 2\ :sup:`31` (whether the child is a hardened key).
 
-  - If so (hardened child): let *I* = PRF\ :sup:`expand`\ (*c*\ :sub:`par`\ , [0x11] || EncodeXSKParts(*ask*\ :sub:`par`\ , *nsk*\ :sub:`par`\ , *ovk*\ :sub:`par`\ , *dk*\ :sub:`par`\ ) || I2LEOSP\ :sub:`32`\ (*i*))
-  - If not (normal child):  let *I* = PRF\ :sup:`expand`\ (*c*\ :sub:`par`\ , [0x12] || EncodeXFVKParts(*ak*\ :sub:`par`\ , *nk*\ :sub:`par`\ , *ovk*\ :sub:`par`\ , *dk*\ :sub:`par`\ ) || I2LEOSP\ :sub:`32`\ (*i*))
+  - If so (hardened child): let *I* = PRF\ :sup:`expand`\ (*c*\ :sub:`par`\ , [0x11] || EncodeExtSKParts(*ask*\ :sub:`par`\ , *nsk*\ :sub:`par`\ , *ovk*\ :sub:`par`\ , *dk*\ :sub:`par`\ ) || I2LEOSP\ :sub:`32`\ (*i*))
+  - If not (normal child):  let *I* = PRF\ :sup:`expand`\ (*c*\ :sub:`par`\ , [0x12] || EncodeExtFVKParts(*ak*\ :sub:`par`\ , *nk*\ :sub:`par`\ , *ovk*\ :sub:`par`\ , *dk*\ :sub:`par`\ ) || I2LEOSP\ :sub:`32`\ (*i*))
     where (*nk*\ :sub:`par`\ , *ak*\ :sub:`par`\ , *ovk*\ :sub:`par`\ ) is the full viewing key derived from
     (*ask*\ :sub:`par`\ , *nsk*\ :sub:`par`\ , *ovk*\ :sub:`par`\ ) as described in [#sapling-key-components]_.
 
@@ -207,7 +207,7 @@ CDKfvk((*ak*\ :sub:`par`\ , *nk*\ :sub:`par`\ , *ovk*\ :sub:`par`\ , *dk*\ :sub:
 - Check whether *i* ≥ 2\ :sup:`31` (whether the child is a hardened key).
 
   - If so (hardened child): return failure
-  - If not (normal child):  let *I* = PRF\ :sup:`expand`\ (*c*\ :sub:`par`\ , [0x12] || EncodeXFVKParts(*ak*\ :sub:`par`\ , *nk*\ :sub:`par`\ , *ovk*\ :sub:`par`\ , *dk*\ :sub:`par`\ ) || I2LEOSP\ :sub:`32`\ (*i*))
+  - If not (normal child):  let *I* = PRF\ :sup:`expand`\ (*c*\ :sub:`par`\ , [0x12] || EncodeExtFVKParts(*ak*\ :sub:`par`\ , *nk*\ :sub:`par`\ , *ovk*\ :sub:`par`\ , *dk*\ :sub:`par`\ ) || I2LEOSP\ :sub:`32`\ (*i*))
 
 - Split *I* into two 32-byte sequences, *I*\ :sub:`L` and *I*\ :sub:`R`\ .
 - Let *I*\ :sub:`ask` = ToScalar(PRF\ :sup:`expand`\ (*I*\ :sub:`L`\ , [0x13]))
@@ -395,7 +395,7 @@ A Sapling extended spending key (*ask*, *nsk*, *ovk*, *dk*, *c*), at depth *dept
 with parent full viewing key tag *parent_fvk_tag* and child number *i*, is
 represented as a byte sequence:
 
-  I2LEOSP\ :sub:`8`\ (*depth*) || *parent_fvk_tag* || I2LEOSP\ :sub:`32`\ (*i*) || *c* || EncodeXSKParts(*ask*, *nsk*, *ovk*, *dk*)
+  I2LEOSP\ :sub:`8`\ (*depth*) || *parent_fvk_tag* || I2LEOSP\ :sub:`32`\ (*i*) || *c* || EncodeExtSKParts(*ask*, *nsk*, *ovk*, *dk*)
 
 For the master extended spending key, *depth* is 0, *parent_fvk_tag* is 4 zero bytes,
 and *i* is 0.
@@ -410,7 +410,7 @@ A Sapling extended full viewing key (*ak*, *nk*, *ovk*, *dk*, *c*), at depth *de
 with parent full viewing key tag *parent_fvk_tag* and child number *i*, is
 represented as a byte sequence:
 
-  I2LEOSP\ :sub:`8`\ (*depth*) || *parent_fvk_tag* || I2LEOSP\ :sub:`32`\ (*i*) || *c* || EncodeXFVKParts(*ak*, *nk*, *ovk*, *dk*)
+  I2LEOSP\ :sub:`8`\ (*depth*) || *parent_fvk_tag* || I2LEOSP\ :sub:`32`\ (*i*) || *c* || EncodeExtFVKParts(*ak*, *nk*, *ovk*, *dk*)
 
 For the master extended full viewing key, *depth* is 0, *parent_fvk_tag* is 4 zero bytes,
 and *i* is 0.