And

is a dyadic scalar boolean function which tests if both arguments are true: it returns 1 if both are 1 and 0 if one or both are 0. It represents the logical conjunction in Boolean logic. In many APLs, And is a special case of the LCM function.

Examples
The following shows all possible combinations of inputs as a Boolean function.

When combined with Reduce, And can be used to test if every value in a Boolean vector is true.

Documentation

 * Dyalog
 * APLX
 * J Dictionary, NuVoc