Combinational mathematics was not new at that time: Pascal, Leibniz, Wallis, the Bernoullis, De Moivre, and Euler, among others, had contributed to it. Hindenburg and his school attempted, through systematic development of combinatorials, to give it a key position within the various mathematical disciplines. "Combinatorial consideration, especially appropriate symbols, were useful in the calculations of probabilities, in the development of series, in the inversion series, and in the development of formulas for higher differentials. The utility led Hindenburg and his school to entertain great expectations: they wanted combinatorial operations to have the same importance as those of arithmetic, algebra, and analysis. They developed a complicated system of symbols for fundamental combinatorial concepts, such as permutations, variations, and combinations." (DSB)