x=: 1j1
   y=: 3.14159j1.2
   x+y            NB. addition
4.14159j2.2
   x*y            NB. multiplication
1.94159j4.34159
   %x             NB. inversion
0.5j_0.5
   -x             NB. negation
_1j_1
   +x             NB. (complex) conjugation
1j_1