and (and verb)
The verb and returns the minimum of its arguments. It applies to all data types except symbol.
q)r:X and Y
q)1100b and 1010b 1000b q)1b and 10b 10b q)1b and 0b 0b
The name and is used because it behaves as logical AND on boolean arguments, but is extended to minimum on other data types:
q)-2 0 3 7 and 0 1 3 4 -2 0 3 4
For a complete list of functions, see the kdb+ Function Reference.