Under the definition of XTDE3362 we say:

"[ERR XTDE3362] It is a dynamic error to call the accumulator-before or accumulator-after function when the context item is a node in tree to which the selected accumulator is not applicable (including the case where it is not applicable because the document is streamed and and the accumulator is not declared with streamable="yes"). Implementations may raise this error but are not required to do so, if they are capable of streaming documents without imposing this restriction."

s/in tree/in a tree/
s/and and/and/

Under 18.2.5 and 18.2.6 we have the line:

"The function returns the pre-descent value B(N)of the selected accumulator where N is the context node, as defined in 18.2.4 Formal Model for Accumulators"

There's a missing dot at the end.
s/B(N)of/B(N) of/   (add a space)