In LK, the RHS may also have any number of formulae—if it has none, the LHS is a contradiction, whereas in LJ the RHS may only have one formula or none: here we see that allowing more than one formula in the RHS is equivalent, in the presence of the right contraction rule, to the admissibility of the law of the excluded middle.
在LK中，RHS也可以有任意数目的公式--如果没有，则LHS是个矛盾，而在LJ中，RHS只能没有或有一个公式：在右紧缩规则前面，允许RHS有多于一个公式，等价于容许排中律。