Design a rule whose LHS always matches anything in the workspace and whose RHS always rewrites so as to leave the workspace unchanged. What happens when you test this rule?
Design a rule whose LHS will match 
name
 in the workspace but will not match 
name@host
. Is this possible with just 
$+
 and 
$*
?
What happens if you arrange rules in a different order? Try reversing the first two rules in our rule set 3.