Word War II has been raging for years, and many innocent words have been rounded up into concatenation camps (which is certainly a death sentence). Thus far, you've managed to evade detection but many of your friends have not been so lucky.
Though it likely spells your doom, you've decided to help and have dug a narrow tunnel into one of the camps through which you'll be able to help a small group of words escape. Unfortunately you can barely get a word in edgewise, so they'll have to come through a few letters at a time. The even bigger problem, is that once on the outside the escapees will need to be disguised or they'll be too easily recognised and risk being caught again.
The night of the escape comes, and a small group of words has gathered near the entrance to the tunnel:
abstruse, condors, honest, invention, neon, reacted, vague
Now it's up to you to help them escape and ensure their disguises are good enough to evade detection on the outside.
- Move words or word fragments from one side of the tunnel to the other until all constituent letters have escaped to the other side
- Word fragments must always be a contiguous sequence of letters taken from the start or the end of a single existing word
- Movement can only occur from one side of the tunnel to the other (i.e. you can't rearrange words whilst still on one side), however you can move through the tunnel in either direction
- Words formed on either side of the tunnel must always be valid dictionary words (see clarifications below), though fragments in transit need not
- In order to remain disguised, any word that appears at any time on one side of the tunnel, must never appear on the other side in the exact same form (the corollary of which is that a word can't move directly in whole from one side to the other)
A simple, one word example (with "@" being the tunnel):
reheat @ ed
heat @ reed
he @ reed, at
here @ ed, at
there @ ed, a
re @ ed, a, the
@ ed, are, the
Clarifications on what constitutes a "word":
To be considered a valid word, it must have an entry on dictionary.com, with the following stipulations:
- English words only
- No acronyms and abbreviations (though shortenings that have become common words, such as "ed" are ok, so long as they're listed as such)
- No proper nouns
- Informal words are ok, but regional specific slang is not
Edit (Oct 6):
I recognise that retrospectively changing things is a little unfair to existing answers (please don't downvote them), but I wanted to make a few further clarifications as to my intentions of what constitutes a word:
- Use of accented characters isn't allowed ("é" is not the same as "e")
- Just having an entry on dictionary.com doesn't make it a word (eg. every letter of the alphabet has it's own entry, but they aren't words, unless it has additional definition, eg. "I" or "a", similarly chemical symbols aren't words)
- Related/Derived forms of a given word are allowed, even when they don't have a page of their own (eg. "test" has a page, and lists things like "testing" and "testability" under derived forms even though they don't have their own individual entry pages)
That being said the English language is by it's very nature fluid, so while I'm trying to be unambiguous, all these rules are going to be somewhat subjective and I'm happy for people to argue their case for exceptions.
Edit (Oct 27):
I've posted my reference solution below, if anyone is interested. It's marked as accepted since it's currently the "best" solution. Still happy to move the tick if anyone can make improvements...
Note: There's potentially multiple solutions to this problem, so if multiple people get it, I'll award the tick to the person who can arrive at the least number of words on the other side of the tunnel (with the least number of steps taken as a tie-breaker). For reference, my solution results in 6 words.