[spec] Fix typo

Author: rossberg

document/core/appendix/properties.rst

@@ -665,9 +665,9 @@ a store state :math:`S'` extends state :math:`S`, written :math:`S \extendsto S'
 
 * For each :ref:`global instance <syntax-globalinst>` :math:`\globalinst_i` in the original :math:`S.\SGLOBALS`, the new global instance must be an :ref:`extension <extend-globalinst>` of the old.
 
-* For each :ref:`element instance <syntax-eleminst>` :math:`\eleminst_i` in the original :math:`S.\SELEMS`, the new global instance must be an :ref:`extension <extend-eleminst>` of the old.
+* For each :ref:`element instance <syntax-eleminst>` :math:`\eleminst_i` in the original :math:`S.\SELEMS`, the new element instance must be an :ref:`extension <extend-eleminst>` of the old.
 
-* For each :ref:`data instance <syntax-datainst>` :math:`\datainst_i` in the original :math:`S.\SDATAS`, the new global instance must be an :ref:`extension <extend-datainst>` of the old.
+* For each :ref:`data instance <syntax-datainst>` :math:`\datainst_i` in the original :math:`S.\SDATAS`, the new data instance must be an :ref:`extension <extend-datainst>` of the old.
 
 .. math::
    \frac{