HELP VED_RESETVARS                   Aaron Sloman and Tim Read, Feb 1994

This is a utility that helps you track down multiple uses of the same
variable in contexts where it should have been declared but has not.

The automatic declaration of undeclared variables normally causes a
warning message to be printed out. E.g.

    hello=>
    ;;; DECLARING VARIABLE hello
    ** <undef hello>

This warning indicates that you should find where you used the variable
and ensure that it is properly declared, e.g. as a local variable.
All such automatically declared variables are, by default, added to the
list popwarnings.

However, sometimes when you have found and corrected some occurrences
of there variable there are others that will not be noticed when you
compile the files containing them because the variable has now been
declared, and so that occurrence will not cause the "DECLARING VARIABLE"
message to be printed out.

This can be overcome by the command

    ENTER resetvars

This has the effect of cancelling all the identifiers that are in
popwarnings, and resetting popwarnings to the empty list.

This means that if you then recompile files that previously caused
warning messages to be printed out, and you still have not properly
declared some of the variables you will again get warning messages.
This can help with elimination of troublesome bugs.