How to write about something in the future where something will have happened


How could I write about something in the future where something will have
happened? That is, I'm writing from the perspective of the current time, about
a perspective in the future where something has happened between the two
perspectives.

My specific case right now is to get the equivalent of "If you are reading
this, I will already be dead" in Japanese.  
Currently I'm thinking of 「これを読んでいるなら、私はもう死んでいました」, but that seems to
translate more to "If you are reading this, I am already dead", that is, the
perspective for it is in the future, but I want to write in the present.

  * "If you are reading this, I will already be dead" ⟵ this
  * "If you are reading this, I am already dead" ⟵ not this

Since this is a bit hard to understand, here's a drawing to explain what I
want to do:

[code]

    Time ───────────────┬────────────────────┬────────────────┬─────────────>
            Now (Writing the letter)       I die        Letter is read
                        └────────────────┐   └────────────────│────────────────┐
                           Writing from here, talking about this, referencing this event
    
[/code]

@YangMuye [suggested turning it into a
question](http://chat.stackexchange.com/transcript/message/15499407#15499407):
「あなたがこれを読んでいるなら、私はもう死んでいるでしょう。」Would this be the best way to do it?

While also helping me with my specific case, please also give a general answer
to the question in case people need to apply it to other sentences such as,
"In the future, androids will have been created", or "At the heat death of the
universe, all black holes will have evaporated" (Yes, I'm bad at examples)




If you're sure you'll die and I'll read your letter after your death, then
you'd say:

> あなたがこの手紙を読むころには、私はもう死んでいるでしょう。  
>  あなたがこの手紙を読んでいるころには、私はもう死んでいるでしょう。  
>  (Literally: I will already be dead when you read this letter.)

If I won't read your letter if you survive, then you'd say:

> あなたがこの手紙を読んでいるということは、私はもう死んでいるということでしょう。  
>  あなたがこの手紙を読んでいるということは、私はもう死んでいるのでしょう。  
>  (Literally: If you're reading this letter, then it means that I'm already
> dead.)

If you're not sure that I'll read your letter, but you're sure that it'll be
only after your death that I can read it, then:

> あなたがこの手紙を読んでいるなら、それは私が(もう)死んだあとでしょう。  
>  あなたがこの手紙を読むとすれば、それは私の死んだあとでしょう。  
>  (Literally: If you read this letter, it will be after my death.)

(Sorry if I'm misreading your question.)




If you're sure you'll die and I'll read your letter after your death, then
you'd say:

> あなたがこの手紙を読むころには、私はもう死んでいるでしょう。  
>  あなたがこの手紙を読んでいるころには、私はもう死んでいるでしょう。  
>  (Literally: I will already be dead when you read this letter.)

If I won't read your letter if you survive, then you'd say:

> あなたがこの手紙を読んでいるということは、私はもう死んでいるということでしょう。  
>  あなたがこの手紙を読んでいるということは、私はもう死んでいるのでしょう。  
>  (Literally: If you're reading this letter, then it means that I'm already
> dead.)

If you're not sure that I'll read your letter, but you're sure that it'll be
only after your death that I can read it, then:

> あなたがこの手紙を読んでいるなら、それは私が(もう)死んだあとでしょう。  
>  あなたがこの手紙を読むとすれば、それは私の死んだあとでしょう。  
>  (Literally: If you read this letter, it will be after my death.)

(Sorry if I'm misreading your question.)

