where - Correlates assertions
#- A list of expressions which must be true for the concept to hold
#- Describes constraints on how reports are to be combined.
e.g. DOS.host is SPS.source
DOS.port_set includes SPS.source
active(DOS) while active(SPS)
#- Base library of functions can be extended either globally or local
to the particular construct.
e.g. defpred is_mail_port(X) (
X in { SMTP, POP, POP2, POP3, IMAP }
deffunc number_of_ports(X) (
#- CBV only, no side-effects
#- No external calls allowed