I could understand the derivation of this $f_n$ for a leaf node but not for a non-leaf node in the $s$.
I could not understand the move from step 4 to 5 ( the last move).
I will be very grateful Can somebody help in understanding the last move here?
How qx(0) = qx(1) /\1(0) . qx(2) /\2(0) . qx(3) /_\3(0) . ... ?
I don't think Lagrange interpolation says this. I think I am missing something here. Please help me in understanding this.
Thanks and Regards