premise: A semi-automatic pistol is a type of pistol that is semiautomatic, meaning it uses the energy of the fired cartridge to cycle the action of the firearm and advance the next available cartridge into position for firing. One cartridge is fired each time the trigger of a semi-automatic pistol is pulled; the pistol's "disconnector" ensures this behavior.
hypothesis: No matter how long you press the trigger it will only fire once
reason: You have to press it again to fire more