[postgis-devel] Topology: how add two edge with a shared node ?

[aperi2007]

Hi,

starting from the story of the closed ticket
http://trac.osgeo.org/postgis/ticket/765

I like to better understand the question:

Starting from the fact that ST_AddIsoEdge(..) give error if try to add 
an edge having a single node shared with another edge.

How is possible to add some edges having all one or two node shared each 
other ?

I search for a function named ST_AddEdge(..) but nothing found.

Thx,

Andrea.