John-Michael KuczynskiDec 19, 20201 min readHow do you differentiate between at least one X and exactly one X in predicate logic?At least one x has F: ExFxExactly one x has F: ExVy(Fy <->x=y)Fx: x is a President. In that case, "there is at least one President" is "ExFx": and "there is exactly one President" is "ExVy(Fy <->x=y)"1 view0 commentsPost not marked as liked

At least one x has F: ExFxExactly one x has F: ExVy(Fy <->x=y)Fx: x is a President. In that case, "there is at least one President" is "ExFx": and "there is exactly one President" is "ExVy(Fy <->x=y)"