In this case, it's just that the decompiler didn't think of "else if" as a single control flow construct/keyword in the way that the original programmers did.

What was no doubt written like this:

  if(a < 1){
  }else if(a < 2){
  }else if(a < 3){
  }else{
  }

Decompiled into this:

  if(a < 1){
  }else{
    if(a < 2){
    }else{
      if(a < 3){
      }else{
      }
    }
  }