To deduce unknown field values from known values, we associate
with every predicate P, a set of rules denoted by ={,...., }. Each rule R has a set of fields
which must be known if the
rule is to trigger and deduce unknown field value.
This set of known field values is collectively termed as mode-rule
and is denoted by
.
={
,
...., 
}. Each rule R has a set of fields
which must be known if the
rule is to trigger and deduce unknown field value.
This set of known field values is collectively termed as mode-rule
and is denoted by
.