How to check if point is on a line starting a hidden paragraph?

[Tassilo Horn]

Hi all,

I need a predicate that checks if the current line after which some
hidden text follows.  I mean those lines ending in an artificial `...'.

Concrete examples are outlines whose contents are hidden, or lines in
gnus summary buffers whose subthread is hidden, or lines after which
more indented text is hidden when using selective-display.

Any ideas?

Bye,
Tassilo