Calling a function inside other function

Hi,

I am having three functions and the data inputs to only one of them. Lets say i have a function A having two parameters a and b. The sum operation is going inside.

def sum(a, b), do: a + b

Then in the second function, I want to add ten to the result of sum(a, b). So i can simply do like

def sum(a, b) do 
a + b
|> add()
end

and then define add.

def add(sum) do
sum + 10
end

Now, my question is that how can I use this sum function and add functions separately. let’s say in a third function I want to take the product of sum and add function. Right now I can’t use them as the sum function is always calling the add function.

def product() do
# code here
add * sum
end