(same as in sample policy 1) We are worried about excessive use of
saxophones in music distributed over the Internet. We trust publishers and
all others to declare honestly the number of saxophones used; we want to
check this number before browsing the URL.
Policy in English
Get the embedded PICS label from the document source. Allow viewing this
URL only if all labels has saxophones rating less than 2 in
"http://www.musac.org" service.
Output
FALSE with a statement containing the PICS label that has sax rating greater
than 2 (the one that justifies the output).
Explanation
This policy is almost identical to Sample Policy 1, except
that the restriction operator within the pattern matcher is "<!"
instead of "<". The "!"-ending restriction
operators require every matching statement that is tested against
the operator to satisfy the operator. The effect is that all
labels from all sources that indicate a sax level must indicate a low
sax level. Thus a
user can choose this policy instead of the last, depending on
how the user wants to resolve simultaneous reception of a label
from Alice saying musac-s level 1 and a label from Bob saying
musac-s level 2.
DIY: Do-It-Yourself
You can change the sax rating in the second PICS label to 0. What
do you expect to get? 'TRUE' with both PICS labels as returned
statements to justify the ouput answer.
Yang-Hua Chu
Last modified: Fri Dec 13 14:32:33 EST