First class functions let square x=X*X let isodd x=x%2<>0 let sumofoddSquares nums nums> List filter isodd> list. sum By square let numbers=[1; 2, 3 4; 5 let sum sumOfoddSquares numbers printf" The sum of the odd squares in %A is %d"numbers sumFirst Class Functions let square x = x * x let isOdd x = x % 2 <> 0 let sumOfOddSquares nums = nums |> List.filter isOdd |> List.sumBy square let numbers = [1; 2; 3; 4; 5] let sum = sumOfOddSquares numbers printfn "The sum of the odd squares in %A is %d" numbers sum