I just want to figure out how to "represent" or to inject an interpolating function into a numerical calculation. So, suppose i have an interpolating function $int$ and then i want to use NDSolve or Rationalize or any numerical operations involving $int$. How do I implement the routine. I have expanded this function using Series and it gave me the output $1+2x+..$ as i desire. But if I do any operation involving only the interpolating function itself, the output includes the interpolating box. How do i properly represent an interpolating function in an operation without the interpolating box appearing in the output? Thanks
Attached is the operation where TPint is the interpolating function.