Intelligent Global Compare wanted

I'm looking for some existing solutions to compare 2 global structures.

- by subscripts
- if subscripts match then by content.

It is not just for     ^X ?= ^Y over identic subsripts
but also for partial subtree structures like    ^X(123,"ABC") ?= ^Y("v1",1,"backup") and then whole tree below.
I just want to check before re-inventing the wheel again.