package geniusweb.profile;

import geniusweb.issuevalue.Bid;

/**
 * Defines a is-better relation between bids. This basically is a partially
 * ordered space however some bids or groups of bids may not be relatable to
 * others.
 */
public interface PartialOrdering extends Profile {

	/**
	 * @param bid1 the first item's utility/preference
	 * @param bid2 the second item's utility/preference
	 * @return true iff bid1 is considered better or equal (≥) than bid 2. In
	 *         all other cases false is returned. A bid may not have a ≥
	 *         relation at all.
	 * 
	 *         This predicate should be implemented such that
	 *         <ul>
	 *         <li>b &ge; b (every bid is better or equal to itself)
	 *         <li>If b1&ge;b2 and b2&ge;b1 then the two bids are considered
	 *         equally good. Note that this differes from a partial order in
	 *         mathematics.
	 *         <li>it behaves transitive: if b1&ge;b2 and b2&ge;b3 then
	 *         b1&ge;b3.
	 *         </ul>
	 */
	boolean isPreferredOrEqual(Bid bid1, Bid bid2);
}