"the reason therefor" vs. "the reason thereof"

[John]

Dear all:

Which of the following two sentences sounds better and clearer?

1. If X failed to prove that a formula in Y is valid, the reason thereof
was not visible.

2. If X failed to prove that a formula in Y is valid, the reason
therefor was not visible.

The intended meaning is the following:

If
the computer program called X failed to derive a proof
of a formula that was written in formalism called Y,
then
it was unclear why the tool failed to derive the proof (maybe, no
proof exists, or the program is not powerful enough).

Any hints?

Thanks in advance
John

[Einde O'Callaghan]

Both of them sound stilted - and indeed incorrect - to me. What's wrong
with saying plainly and simply: "... the reason for this was not
visible" or even "... was unclear"?

Regards, Einde O'Callaghan

[John Hall]

In article <9bnf22...@mid.individual.net>,

Agreed. Another possibility is "the reason why was unclear".
--
John Hall
"Men occasionally stumble over the truth, but most of them pick
themselves up and hurry off as if nothing ever happened."
Winston S Churchill (1874-1965)

[jaakov]

Interesting... What grammatical rule would it break?

[Einde O'Callaghan]

"Therefor" and "thereof" are both very old-fashioned - indeed obsolete
in modern English - they sound very 16th century along with other
obsolete forms such as "thou", "thee", "thy" and "thine", "hath",
"hast", "he cometh not" etc.

While "therefor" could - at a push - be considered grammatically correct
because it's based on the preposition "for" (as in "reason for"),
"thereof" is definitely incorrect because "of" isn't the preposition
that goes with "reason" in modern English.

Regards, Einde O'Callaghan

[John]

Great, thank you! Now how about "the reason why" vs. "the reason for
this" vs. "the reason for that", i.e.:

3. If X failed to prove that a formula in Y is valid, the reason why was
not visible.
4. If X failed to prove that a formula in Y is valid, the reason for
this was not visible.
5. If X failed to prove that a formula in Y is valid, the reason for
that was not visible.

John.

[Einde O'Callaghan]

All of them sound OK to me. To a great extent whether you use "this" or
"that" would depend on the context.

Regards, Einde O'Callaghan

[John]

>> 3. If X failed to prove that a formula in Y is valid, the reason why was
>> not visible.
>> 4. If X failed to prove that a formula in Y is valid, the reason for
>> this was not visible.
>> 5. If X failed to prove that a formula in Y is valid, the reason for
>> that was not visible.
>>
> All of them sound OK to me. To a great extent whether you use "this" or
> "that" would depend on the context.

I see. Wonderful, thanks!
John.