[RULES]

Purpose:

Defines rule-based controls which modify links based on a combination of conditions.

Format:

Each rule is a series of statements of the form:

RULE   ruleID
IF       condition_1
AND   condition_2
OR     condition_3
AND   condition_4
etc.
THEN  action_1
AND   action_2
etc.
ELSE  action_3
AND   action_4
etc.
PRIORITY value

where:

ruleID	=	an ID label assigned to the rule
conditon_n	=	a condition clause
action_n	=	an action clause
PRIORITY	=	a priority value (e.g., a number from 1 to 5)

Remarks:

1. Only the RULE, IF and THEN portions of a rule are required; the other portions are optional.
2. When mixing AND and OR clauses, the OR operator has higher precedence than AND, i.e.,
         IF A or B and C
   is equivalent to
   
         IF (A or B) and C
   If the interpretation was meant to be
         IF A or (B and C)
   then this can be expressed using two rules as in
         IF A THEN ...
      IF B and C THEN ...
   
3. The PRIORITY value is used to determine which rule applies when two or more rules require that conflicting actions be taken on a link. A rule without a priority value always has a lower priority than one with a value. For two rules with the same priority value, the rule that appears first is given the higher priority.

Example:

[RULES]
RULE 1
IF   TANK   1 LEVEL ABOVE 19.1
THEN PUMP 335 STATUS IS CLOSED
AND  PIPE 330 STATUS IS OPEN 
 
RULE 2
IF   SYSTEM CLOCKTIME >= 8 AM
AND  SYSTEM CLOCKTIME < 6 PM
AND  TANK 1 LEVEL BELOW 12
THEN PUMP 335 STATUS IS OPEN 
 
RULE 3
IF   SYSTEM CLOCKTIME >= 6 PM
OR   SYSTEM CLOCKTIME < 8 AM
AND  TANK 1 LEVEL BELOW 14
THEN PUMP 335 STATUS IS OPEN