ERN varname
ERN varnamelist

Erases the variable(s) named in the input from the workspace. ERN abbreviates ERASE NAMELIST.

It is possible to erase variables which shadow another variable through dynamic scoping. In this case, the variable remains erased until it would have gone out of scope, at which time the shadowed variable reappears in the workspace with its former value.

MAKE "foo 1
MAKE "bar 2
PONS
Make "bar 2
Make "foo 1
ERN [foo]
PONS
Make "bar 2