Tcl 8.4 has a new core command lset which conflicts with the Hume dmh package use of this name. The Hume dmh package lset command is being migrated to vset so you can use the new core command along with the Hume command. To run the same application code in Tcl 8.3 and Tcl 8.4, you can begin to use vset instead of lset. Versions of the Hume software built after September, 2002, include vset and also support the new commands dmh_import and dmh_var which have been created to support deploying applications that are compatible with both Tcl 8.3 and 8.4.
In Tcl 8.3, the vset command is implemented as an alias. The implementation code is similar to:
# This definition is here to fool the indexing logic:
proc vset {data names} { return [lset $data $names] }
# better performance is obtained using alias
rename vset {}
interp alias {} vset {} lset