> a word is not eliminated by a guess if and only if the result of testing the word against the solution is the same as the result of testing the guess against

> a word is not eliminated by a guess if and only if the result of testing the word against the solution is the same as the result of testing the guess against the solution That's not true. Suppose the actual word is "abcdx" but the guessed word is "xefgh". The result of testing is Yellow-Black-Black-Black-Black. Now suppose you have other words like "xijkl" that will test against the solution in exactly the same way (Yellow-Black-Black-Black-Black), but you know won't be the correct solution because in the first round the misplaced "x" already tells you "x" should be present at a different position. So now we have a word that can be eliminated even if it tests against the solution in the way the guessed word does.