A reference removed from scope within the current subtree (e.g., via rm). Like out references, kills bubble up so the enclosing scope can apply the removal at the right location.
rm
a statically known name (carries IdentifierReference#cds|cds for conditional removals)
the whole current scope is cleared, e.g., rm(list = ls())
rm(list = ls())
a not statically resolvable set of names, e.g., rm(list = someVector)
rm(list = someVector)
applyKills
A reference removed from scope within the current subtree (e.g., via
rm). Like out references, kills bubble up so the enclosing scope can apply the removal at the right location.