Loops

• A loop repeats something over and over again
• A rule or set of a rules can implement a loop
• For one rule you need to keep the LHS true but change one of the data items it depends on.
• For example
• if (value ?a) (test (< ?a 5) then (assert (value (+ ?a 1))
• You get ?a, see if it is less than 5, and if so assert a new fact. The next cycle this exact rule will be rerun again until (value 5).
• This is the basic idea for any loop.
• They can also benefit from an initialisation and conclusion rule.