This paper introduces a software tool named SPIDERS which uses a novel iterative algorithm to derive prime implicants from logic functions. The algorithm takes the logic function as a list of binary numbers indicating the minterms to be disjointed. The numbers are first sorted using a special sorting algorithm with a time complexity of order O(n). Then they are rotated and sorted again in each iteration. Thus, the ith iteration of the algorithm places minterms differing only in the ith literal in successive locations of the list. By doing so, prime implicants appear as consecutive blocks of numbers in the list. The SPIDERS algorithm exhaustively derives all prime implicant from the input function during a number of iterations which is equal to the number of logic variables.