Error XTSE3195 reads as:

"[ERR XTSE3195] If the for-each-item is present then the for-each-source, use-accumulators, and streamable attributes must both be absent. If the use-accumulators attribute is present then the for-each-source attribute must be present. If the for-each-source attribute is present then the for-each-item attribute must be absent. "

But the prose doesn't cover the scenario where neither for-each-item and for-each-source are present, but streamable is present.

I think the intent of this error is to prevent confusion with streamable="yes" and disallows its appearance in any other scenario unless for-each-source is also present.

If we were to allow streamable="yes" with an absent for-each-stream, we'd run into conflict with the streamability rules for xsl:merge, which requires all expressions to be grounded and motionless. So the potential streaming input in that case would end up being non-streaming anyway.

I suggest we fix it simply by adding the case to the error, for instance something like this:

"[ERR XTSE3195] If the for-each-item is present then the for-each-source, use-accumulators, and streamable attributes must both be absent. If the use-accumulators *** and/or streamable *** attribute is present then the for-each-source attribute must be present. If the for-each-source attribute is present then the for-each-item attribute must be absent. "