How would I go about adding this formula:

IF(OR(Left_Fin_End=1,Right_Fin_End=1),-.5,"")

To this formula: 

=IF(Bulge=0,Front_Build_Up_Length,IF(Bulge>1,PANELLENGTH_2,IF(Bulge<-1,PANELLENGTH_2,Front_Buildup_Length_Calc)))


Basically I am trying to come up with a formula that if the left or right finished ends are selected in product prompts, the buildup for the countertop will decrease by .5 for each side, sometimes both.