The fusion gate (figure (a)) was first implemented in fluidic devices in the 1960s. The gate is the most well known (on a par with the bistable amplifier) device in fluidics : two nozzles are placed at right angles to each other, when there are jet flows in both nozzle they collide and merge into a single jet entering the central out-let. If the jet flow is present only in one of the input nozzles it goes into the vent. The central outlet represents and and the vent represent and-not. The fusion-based gate was also employed in designs of computing circuits in Belousov-Zhabotinsky medium , where excitation wave-fragments merge when collide; in the actions of slime mould , when distributing vesicles collide; and a crab-based gate , were swarms of solider crabs merge into a single swarm. In the annihilation gate (figure ) signals disappear on impact. This gates has two-inputs and two-outputs, each of the outputs represents and-not. Computational universality of the Conway's Game of Life cellular automata was demonstrated using annihilation based collisions between gliders . We can also implement the annihilation gate by colliding excitation wave-fragments at certain angles .