For real condition (not hypothetical) of simple present and past and hearsay, you should use var/yok

if there is x = x var ise

if there is not x = x yok ise

if there was x yesterday = dün x vardı ise

if there was not x yesterday = dün x yoktu ise

if there is said to be x = x var imiş ise

if there is not said to be x = x yokmuş ise

if there was said to be x yesterday = dün x varmış (idi) ise

if there was not said to be x yesterday = dün x yokmuş (idi) ise

When you talk about real conditions do you mean like types I and II in the above system? (It´s dull to ask the same things always, I know, but it´s vital to understand the terminology.)

Yes but that list does not mention past tense forms.