Would have had to have called...

#1 clearly has another layer of perfection. In #2, the call is made (or initiated, or placed) by 8:00. In #1, the call has been completed by 8:00.
The difference is theoretical rather than practical, because the gap between the two may be infinitely small.
How long does it take to call a cab? If you call a cab at 8:00, you surely will have called it by 8:01

I don't see where the "extra perfect" effects the ambiguity of speculating on what might have happened vs. suggesting what she should have done.
I'm not acquainted with the rules for past imposslble tense and past real tense (way past).

So I guess I'd say the two sentences are equavalent in effect but not in grammar. I believe the native ear hearing one today and the other

Musicgold

Are the following sentences equivalent? ...

1. For Dorothy to have been able to catch the 10:00 pm train, she would have had to have called a cab by 8:00 pm.

2. For Dorothy to have been able to ca

Thanks folks.

CalifJimI don't follow the line of reasoning regarding 'past real' and 'past impossible'

Sorry for the confusion. I was trying to understand if statement 1 was a past real conditional or a past unreal conditional. I am trying to understan

MusicgoldI am trying to understand whether Dorthy could actually catch the train.

Yes. She certainly could -- if she called the cab in time, of course.

CJ

This "real/unreal" stuff is peaking my curiosity.
You could say, "Well, she didn't catch the train, so therefore she must not have called the cab. (Is that what you mean by "unreal"?)
Or you could say, "Well, she caught the train, so therefore she must have called the cab."
"She caught the train" is true. Is that "real"?
You could also turn it around: She didn't call the

CalifJim Yes. She certainly could -- if she called the cab in time, of course.

Ok, so you are saying she did catch the train.

I have seen some people using this structure ( to have been able to .... would have had ) while discussing hypothetical situations. For example, had Dorthy missed the train, then somebody, while assessing the reasons w

MusicgoldOk, so you are saying she did catch the train.

No, no, no!!!

caught the train (=did catch the train) is not the same as could catch the train.

The sentence is entirely about the possibility of catching the train. It doesn't say anywhere in this sentence that she caught the train. Provided

CJ and Avangi have already covered pretty much everything on the sentences as posted.

I'd like to add two more cents if I may.

No doubts, these are conidtional sentences. To me, the sentences are a bit too tedious and could be simplified for the intended meaning without the heaviness to the ears. I would simply revise it to:

For Dorothy to have gotten on / caught the

CalifJim It doesn't say anywhere in this sentence that she caught the train.

. . . . The possibility of catching the train was there because of the call for the cab. It doesn't say anywhere in this sentence that she called a cab.

MG, would you be kind enough to cite a reference for the past real/past impossible concept you're talking