Preimage: Difference between revisions

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 == Image ==
-If "preimage" is a thing, then "image" must be a thing, too.
+The "preimage" is literally "that which came before the image", or in other words, the set of possible things that the image might have been projected from.
-The general mathematical definition of "function" is something that for any given input always returns the same output. A [[mapping]] in RTT thereby qualifies as a function; it always maps any given interval to only a single other interval. In fact, this is essentially the meaning of the word "regular" in the term "regular temperament." And so, the '''image''' for an interval under a (regular) temperament is that one interval that it's mapped to.
+A [[mapping]] in RTT always maps any given interval to only a single other interval. The '''image''' for an interval is that one interval that it's mapped to by a (regular) temperament.
 We can also speak of the "image of a temperament", in general. This means the set of all intervals that can be mapped to.