Update extends fibers into definition

[anitacaron]

(...)
(b) I think the definition of 'extends fibers into' should avoid cases like this:
"there are also neurones that pass through the otic ganglion that do not synapse in the ganglion"

suggested def:

X extends_fibers into Y iff there exists some neuron(n) n has_soma_location(RO:0002100) x and n 'has synaptic IO in region'(RO:0013001) Y

I think it would be safe to add this property chain as I believe has_soma_location has domain neuron.

has_soma_location o 'has synaptic IO in region' -> 'extends_fibers_into'

Originally posted by @dosumis in #2589 (comment)