Final answer:
The pusher and puller most likely get their inputs from a hydraulic system, which uses pressure transmitted through fluid to increase or decrease force.
Step-by-step explanation:
The pusher and puller mechanisms mentioned in your question typically get their inputs from either a hydraulic system, an electrical system, or a pneumatic system. These systems serve as sources of power, enabling the pusher and puller to exert force. Considering the references you provided were exclusively about hydraulic systems, we can infer that, in this case, the pusher and puller are likely driven by a hydraulic system (A).
Hydraulic systems operate on the principle that pressure applied at one point is transmitted undiminished to another point, using an incompressible fluid. The output force of a hydraulic system can be changed by varying the size of the pistons involved, as described in the examples you've shared. For instance, if a 100-N force is applied to a cylinder connected to another cylinder with five times the area, the output force would be 500 N. This mechanism makes hydraulic systems analogous to mechanical levers but with the added benefit of delivering power through curves and to multiple locations simultaneously.