Fixed several bugs in the tree-equal function, as exposed by the tests.
Fixed several bugs in the tree-equal function, as exposed by
the tests.

vtomole/SICL,clasp-developers/SICL,vtomole/SICL,vtomole/SICL,clasp-developers/SICL,clasp-developers/SICL,clasp-developers/SICL,vtomole/SICL