The monad is equivalent to a zero left argument;
that is,
m b. y ↔
0 m b. y
If
f is a dyadic boolean function and
d=: 0 1 ,
then
d f/ d (or
f/~d)is its complete table.
For example the tables for
or,
nor,
and, and
not-and appear as follows:
(+./~ ; +:/~ ; *./~ ; *:/~) d=: 0 1
+---+---+---+---+
|0 1|1 0|0 0|1 1|
|1 1|0 0|0 1|1 0|
+---+---+---+---+
If ordered by their tables, each of the sixteen possible boolean dyads
can be characterized by its index
k ;the
phrase
k b. produces the corresponding function.
Moreover, negative indexing and array arguments may be used.
An atom
m=16+k specifies bitwise boolean functions on integer arguments.
An argument atom is treated as a list of length
w of bits,
where
w is the word size of the underlying machine.
For example,
17 b. specifies bitwise
and.
Finally,
32 b. specifies
rotate,
33 b.
specifies
shift, and
34 b. specifies
signed shift.