We say that two named templates are "compatible" (one can override the other) if (in effect) they have the same parameter definitions.

We should require that the xsl:context-item declaration is consistent as well. Otherwise a non-streamable template could override a streamable one. More specifically, the sweep of xsl:call-template depends on whether " the referenced template has a child xsl:context-item element with the attribute use="prohibited"", which means that streamability can only be determined if we know this property will remain true of any overriding templates.