diff --git a/src/Lib.hs b/src/Lib.hs
index 11a599af4ee611591ba6a4d6f71c001c956d2ceb..927a748b5ca10f2a7e6793c8b3ca8f4ed8b03cd4 100755
--- a/src/Lib.hs
+++ b/src/Lib.hs
@@ -37,3 +37,5 @@ powervalue m = 1 / (power (1 + interest) m)
 -- anonymus function
 factorpresentvalue = map (\x -> powervalue x) [1..5]
 
+-- high order function
+presentvalue = zipWith (*) (netcashflow income outcome) factorpresentvalue