Note that the ASCII character set for \s-2APL\s0 uses both upper-case
and lower-case.

a-z             letter
0-9             digit
`               negative sign
'--'            string
C <bs> J  C     comment
.
( )
[ ; ]           indexing
L               quad
L <bs> '        quot quad

                dyadic  monadic
+               add     plus
\-               sub     negate
X               mult    sign
%               div     recip
|               mod     abs
D               min     floor
S               max     ceil
*               pwr     exp
O <bs> *        log     loge
O               circ    pi times
' <bs> .        comb    fact
!               comb    fact
^               and
V               or
^ <bs> ~        nand
V <bs> ~        nor
<               lt
>               gt
$               le
&               ge
=               eq
#               ne
~                       not
?               deal    rand
R               rho     rho
I               iota    iota
E               epsilon
N               represent
B               base
\\ <bs> O        trans   trans
,               cat     ravel           *
Y               take
U               drop
{               assign
}                       goto
B <bs> N        i-beam  i-beam
L <bs> %        mat div inverse
| <bs> H        grade up                *
G <bs> |        grade down              *
B <bs> J                execute
N <bs> J                format
/               comp                    *
/ <bs> -        comp
\\               expand                  *
\\ <bs> -        expand
O <bs> |        rotate  reverse         *
O <bs> -        rotate  reverse
op /                    reduce          *
op / <bs> -             reduce
J.op            outer product
op.op           inner product

* may be subscripted with a scalar
<bs>  backspace (ctrl h)
