Abstract—This paper investigates threshold based neural networks for periodic symmetric Boolean functions and some related operations. It is shown that any n-input variable periodic symmetric Boolean function can be implemented with a feedforward linear threshold-based neural network with size of O(log n) and depth also of O(log n), both measured in terms of neurons. The maximum weight and fan-in values are in the order of O(n). Under the same assumptions on weight and fan-in values, an asymptotic bound of O(log n) for both size and depth of the network is also derived for symmetric Boolean functions that can be decomposed into a constant number of periodic symmetric Boolean subfunctions. Based on this results neural networks for serial binary addition and multiplication of n-bit operands are also proposed. It is shown that the serial addition can be computed with polynomially bounded weights and a maximum fan-in in the order of O(log n) in O(n= log n) serial cycles, where a serial c...