1. A computer program product for automatically verifying determinism of a structured parallel program, the computer program product comprising: a non-transitory computer readable storage medium having computer readable program code embodied therewith, the computer readable program code comprising: computer readable first program code configured to sequentially establish whether second program code in each of a plurality of tasks of the structured parallel program is independent, configured to output sequential proofs corresponding to the independence of the second program code in each of the plurality of tasks and configured to determine whether all memory locations accessed by the plurality of tasks are independent based on the sequential proofs, wherein the first program code determines for each second program code whether a first program label is present within the second program code that accesses a same array via an index variable within the second program code, wherein the first program code determines for each index variable all values the corresponding index variable is capable of reaching using at least one second program label within the corresponding second program code to determine an over-approximated range of values, wherein each range is represented as a linear inequality using the corresponding index variable; and wherein the first program code determines two or more of the second programs codes are independent when the determined ranges are non-overlapping with respect to the same array.