As it turns out, the original proof had a delicate mistake, which has been since corrected.

The original proof of was long and involved.

During the journey, the passenger will have to produce original proof of identity indicated on the ticket.

The book of the Cornell conference also contained simplifications to the original proof.

Euclid's original proof adds a third: the two lengths are not prime to one another.

The original proof (due to Grothendieck) was never published.

This describes the original proof of the index theorem.

On the other hand, Choi's original proof involves direct calculation of those operators.

The original proof shows that for overlapping reads and writes to the same storage cell only the write must be correct.

Pick's original proof was based on Blaschke products.

The original proof of Harish-Chandra was a long argument by induction.

The original proof was given by Joseph Wedderburn in 1905, who went on to prove it two other ways.

The original proof was bijective and generalized the de Bruijn sequences.

Banach's original proof can be broken off into several Lemmas:

Some cambios will not cash traveler's checks without the original proof of purchase receipt.

Bott's original proof used Morse theory; subsequently, many different proofs have been given.

His original proof was much simplified by P. M. Ross.

The original proof of the switching lemma involves an argument with conditional probabilities.

The original proof that the Hausdorff-Young inequality cannot be extended to is probabilistic.

It is a famous open problem whether this bound can be improved asymptotically (modified versions of the original proof give 2t-1 or even 2t-3).

Proof: See, for instance, for the original proof or for a more recent development.

Weyl's original proof was analytic in nature: it famously used the unitarian trick.

Kodaira gave a streamlined version of Weyl's original proof.

Newman's original proof was considerably more complicated.

The above is essentially Choi's original proof.