So the process is recursive in that you keep drilling down the
input tree and processing the children, and then their children, and so on.
But it can also come to a dead end. The drilling-down process requires that
we receive an instruction to continue applying templates (using the
<xsl:apply-templates> element).
In the diagram, we can see that the <xsl:apply-templates> instruction
is really the key to everything past step 3. It is this element that allows
the stylesheet to process any children of <lg> (i.e. <opener>,
<l>, and <byline>). If this element is absent, nothing
else happens. The stylesheet isn’t instructed to process more children, so
the children are ignored.
Note that although this diagram does not show how each <l> element is
processed, each would treated in the same way as the first two in the output
document (that is, transformed into HTML <p> elements.
