TCL based assertion for connectivity check

Hi,

 I am using ncsim and i wish to check connectivity between two nets in RTL/netlist using tcl. I remember there being someway where using tcl input file i could specify two nets which could be tested for connectivity.

ex:
 -src net1  -dst net2

on a change of net1 check net2 value is equal to net1 value. kind of an tcl assertion

I dont remember the syntax. kindly help

thnaks!
Harsha