UML14 — Outgoing edges from input pins

(Quote from Semantics of CompleteStructuredActivities) "An object
node attached to a structured activity node is accessible within the
node. The same rules apply as for control flow. An input pin on a
structured activity node implies that no action in the node may begin
execution until all input pins have received tokens. An output pin on
a structured activity node will make tokens available outside the
node only after no tokens left in the node or its contained nodes
recursively."

So input pins on structured activity nodes are "accessible within the
node" (as one would expect), but a constraint on InputPin says "input
pins have incoming edges only". So how are they accessed from within
the structured activity node? Analogous question for output pins of
structured activity nodes, which can have outgoing edges only.

see above