Family-Rule: If a message is from someone who belongs-to the family of Fred then the message is important.
Daisy-Rule: If a message is from Daisy then the message is not important.
Emergency-Rule: If a message is a notification of an emergency then the message is important.
Daisy-Rule overrides Family-Rule.
Emergency-Rule overrides Daisy-Rule.
Emergency-Rule overrides Family-Rule.
If there is an illness of someone who belongs-to the family of Fred then the illness is an emergency.
Betty belongs-to the family of Fred.
Daisy belongs-to the family of Fred.
"Item19" is from Betty.
"Item20" is from Daisy.
"Item115" is from Daisy.
"Item115" is a notification of an illness of Daisy.