I am having trouble understanding what is going wrong when trying to use the Coefficient function on expressions in InputForm. A very simple example serves to illustrate.
In:= a = 3 x + 4 y // InputForm Out//InputForm= 3*x + 4*y In:= Coefficient[a, x] Out= 0
Is there any way to make this work, or convert the old expression back into Standard form? Cheers!