Sutra of Tranquil thoughts, unclear how much XP

Question

I have question in regards to the

Sutra of Tranquil thoughts, ML20th

This monastic tome describes ancient techniques of mental focus and is highly prized by psionic practitioners. If a psionic character who is not evil studies the work during one week of solitary contemplation, he gains 17 bonus power points and experience points sufficient to place him halfway into the next level of experience. Those who use their powers for evil are punished for their impertinence in defiling the book; they are permanently drained of 1d4+1 points of Constitution and must atone (via the atonement spell) in order to gain any further experience. In addition, an evil psionic reader must make an immediate DC 15 Will save or become permanently confused as if affected by the psychosis power. Only psychic chirurgery or similarly extreme measures can restore sanity.

The minds of nonpsionic beings are too clouded to benefit from the secrets of this book. To anyone without psionic aptitude, the book’s pages appear to contain nothing but elaborate patterns and drawings of mysterious beings. Once it is read, the book vanishes into the Astral Plane to an unknown destination. Even if it is found again, the same character cannot benefit twice from perusing its contents.

The DM and I are both non-native readers of English and are debating how this should be read. There are two ways we see this could be read:

1. Halfway into the next level. Meaning when you when you are Level 17, you will immediately go to Level 18 and receive half the XP needed to go to Level 19. Thus if you are at 1,300,000 xp, you will immediately go to 1,800,000xp and then receive (2,550,000 - 1,800,000)/2 = 375.000xp on top of a potential maximum of 500.000xp.

2. Half of the XP of your current level towards the next level. If you are Level 17 and are at 1,300,000XP, you will receive (1,800,000xp - 1,300,000xp) / 2 = 250.000xp

So in short, how much XP does the Sutra of Tranquil thoughts actually grant?

Answer 1

"...experience points sufficient to place him halfway into the next level of experience."

This is pretty clear wording, and is basically unchanged from multiple previous RPGs Pathfinder is closely related to (editions 1st to Revised 3rd, at least). This wording has always been used on the various Manuals, and those Manuals have always given you enough experience to level up once and then enough more to put halfway to the next one. Your option 1 is correct.