Read the excerpt below and answer the question.

we can not absolutely know that all these exact adaptations are the result of preconcert. but when we see a lot of framed timbers, different portions of which we know have been gotten out at different times and places and by different workmen—stephen, franklin, roger, and james, for instance—and when we see these timbers joined together, and see they exactly make the frame of a house or a mill, all the tenons and mortices exactly fitting, and all the lengths and proportions of the different pieces exactly adapted to their respective places, and not a piece too many or too few—not omitting even scaffolding—or, if a single piece be lacking, we can see the place in the frame exactly fitted and prepared to yet bring such piece in—in such a case, we find it impossible not to believe that stephen and franklin and roger and james all understood one another from the beginning, and all worked upon a common plan or draft drawn up before the first lick was struck.

in at least one hundred words, what inference does lincoln make in this part of his “a house divided” speech? what language does he use to make this inference?