When the program is first downloaded , Input_2 is '0' because input_2 has to be manually entered from HMI. So after the program is downloaded, The rexlang block does not produce output_y0 .On checking rexview, the iE code says error - division by zero. Later, even when a positive value is entered from HMI, it still does not produce output_y0.  The issue has been solved with a bit of if, else logic as in if in input_2 is zero , Output_y0= some initial constant value.

Im not sure if this is a bug or it is intentional, just thought id share it on the forum. Thanks !