<breed>-neighbor? link-neighbor? 4.0
<breed>-neighbor? turtle
link-neighbor? turtle

Reports true if there is a link (either directed or undirected, incoming or outgoing) between turtle and the caller.
crt 2
ask turtle 0
[
create-link-with turtle 1
show link-neighbor? turtle 1 ;; prints true
]
ask turtle 1
[
show link-neighbor? turtle 0 ;; prints true
]