Part 1: A bomber is on a mission, accompanied by two escort planes. An enemy fighter attacks. In the absence of the attack, the bombing mission will be successful. In the absence of the escorts, the attack on the bomber will be successful and the bombing mission will fail. Either escort is sufficient to stop the fighter. Does shooting down the fighter by one of the escorts cause the bombing attack to succeed?
Part 2: If for some reason, the first escort fails to shoot down the fighter, but the second escort succeeds, does the failure of the first escort cause the second escort to succeed?