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| Module: | Maybe |
|---|---|
| Function: | isNothing |
| Type: | Maybe a -> Bool |
| Description: | returns True if the argument is Nothing |
| Related: |
Input: isNothing (lookup 32 [(1,'A'),(2,'B'),(3,'C')])
Output: True
Input: isNothing (lookup 3 [(1,'A'),(2,'B'),(3,'C')])
Output: False