/* dtf.kb */


low( days_to_flight, 0 ).
high( days_to_flight, 62 ).
scale( days_to_flight, 'days' ).
fuzzy_set( days_to_flight, few_days , down(0, 32) ). % Less than half the timeline remaining.
fuzzy_set( days_to_flight, many_days, up(30, 62) ).  % More than half the timeline remaining.

low( price_increase, 0 ).
high( price_increase, 100 ).
scale( price_increase, 'percent' ).
fuzzy_set( price_increase, low     , down(0, 25) ).     % Minimal increase in price.
fuzzy_set( price_increase, moderate, tri(20, 50, 75) ). % Noticeable increase but not extreme.
fuzzy_set( price_increase, high    , up(70, 100) ).     % Highest increase in price.


if days_to_flight be many_days
then 
   price_increase := low.

if days_to_flight be few_days
then 
   price_increase := moderate.