IF Coding question

[simafrog <SimaFrog@xxxxxxxxxx>]

I am trying to understand the point/reason for this code:
      TOT1a   IFEQ TOT2a                   
      TOT1b   ANDEQTOT2bC                   
              ELSE                         
              EXCPTHEADR                   
              EXCPTTOTAL                     
              ENDIF          
Why do you need the "IF" "AND" part? What purpose does this serve?

Thank you,
Rob400