(01)initializeTransaction(Tr)
(02)For
(03) = extractEvaluationObjectAndAttribute( );
(04) =  getTime( );
(05) initializeClassCounter( );
(06) For
(07)  if
(08)    = getNumericalValue ;
(09)    = calculateChangeRatio ;
(10)    = identifyClassForEvaluationObject ;
(11)    + = 1;
(12) = identifyClassForElement( );
(13) if
(14)  Tr[ ] = addTransaction ;
(15)For
(16) [ ] = discoverFrequentPattern ;
(17) [ ] = extractTrendRule ;
Algorithm 1: Pseudocode for learning trend rules.