ansi .6.2.0260
<CORE>
returns a logical-value saying if the value was not-zero.
This is most useful in turning a numerical value into a
boolean value that can be fed into bitwise words like
AND and XOR - a simple IF or WHILE doesn't
need it actually.
reference: p4_zero_not_equals in ../src/core.c:2008, export CO 0<>