Added method on BODY-FORM specialized to SUM-IT-CLAUSE.
Added method on BODY-FORM specialized to SUM-IT-CLAUSE.

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