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(- number &rest numbers)

With one argument, returns its negation. With several, subtracts the rest from the first, left to right. The result type follows the usual numeric contagion: integers stay integers, but any float argument makes the result a float, and ratios are kept exact. Integer results promote to big integers on overflow, on every backend. The subtraction runs one pair at a time, so the arguments ahead of the first float subtract exactly and only their difference turns into a float: (- 1/10 -1/5 0.0) is 0.3, as in SBCL. A complex argument folds the same way: (- z z 1.5) over an exact complex z is -1.5.