I don't get the meaning of the sign <<>> and also from which line the error is coming as I have a program of more than 30 lines with many defined functions without using "Module" . Is not there any way to display line numbers in Mathematica so that we can know from which line error is coming?
<< ..>> is called a Skeleton. It is is used to show you an abbreviated version of the actual offending line. You can find it in
You can see the skeleton right there in the middle.
The error message probably comes from an illegal construction like:
I think you used a function and then tried to manually set another value to it. for instance:
fun=3; fun[x_]:=Tan[x]; gives the following error
"SetDelayed::write: "Tag Integer in 3[x_] is Protected"
you are probably doing something very similar.