请问这个R语言怎么补全

## 双正态总体-均值的置信区间
mu2_Interval_Estimate<-function(x, y, 
                             sigma=c(-1,-1),var.equal=FALSE, alpha=0.05){ 
  m<-length(x); n<-length(y)
  xb<-mean(x); yb<-mean(y)
  if (all(sigma>=0)){
    tmp<-qnorm(1-alpha/2)*sqrt(sigma[1]^2/m+sigma[2]^2/n)
  }else{
    if (var.equal ==  TRUE){
      Sw<-((m-1)*var(x)+(n-1)*var(y))/(m+n-2)
      tmp<-sqrt(Sw*(1/m+1/n))*qt(1-alpha/2,m+n-2)
    }else{
      tmp<-qnorm(1-alpha/2)*sqrt(var(x)/m+var(y)/n)
    }
  }
  data.frame(a=xb-yb-tmp, b=xb-yb+tmp)
}