+ Conjugate • Plus
Conjugate +  0 0 0 Plus

+ y is the conjugate of y . For example, +3j4 is 3j_4 .
 		   + is defined as in elementary arithmetic, and is extended to complex numbers as usual.
 

A complex number y multiplied by its conjugate produces a real number equal to the square of its magnitude |y . For example:
   3j4 * 3j_4
25
The function j. multiplies its argument by the square root of negative one: 
   ]i=: i. 5
0 1 2 3 4

   j. i
0 0j1 0j2 0j3 0j4

   ]y=: i + 2 * j. i
0 1j2 2j4 3j6 4j8

   +y
0 1j_2 2j_4 3j_6 4j_8

   y * +y
0 5 20 45 80

   %: y * +y
0 2.23607 4.47214 6.7082 8.94427

   |y
0 2.23607 4.47214 6.7082 8.94427
The conjugate of y can also be expressed as (|y*y)%y . For example:
   (|y*y)%y
0 1j_2 2j_4 3j_6 4j_8