I assume it means 10 or 11 or 12,13,14,15,161,17,18 or 19 but if so how does it work? Is 10 … 19 a single object? or is case … a different notation?
case val1 ... val2 is used to write a case when a certain range of input generates the same outcome. So, instead of writing 10 cases with the same outcome, we simply create a case with values ranging from 10–19 that have the same output result.
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