specifies what action should be taken on defining external symbols in certain packages. It is designed to protect against (re)definition of symbols in implementation packages.
The protected packages are those specified in the variable *packages-for-warn-on-redefinition*.
is set to
then you are warned. If it is set to
, the definition is done quietly. If, however, it is set to
, then LispWorks signals an error.
LispWorks User Guide and Reference Manual - 21 Dec 2011