First, I was in error (in an earlier post) when I indicated that "NULL"
was
a figurative constant. This may (or may not) be true for some extension
to
the '85 Standard - but it is NOT true for the '02 Standard.
Rather it is defined as "8.4.2.10 Predefined-address" (see page 98)
and/or
"predefined object reference" (see page 96)
NEITHER of these is valid as the "Selection-subject" in an EVALUATE
statement.
See for example SR(1) on page 98 (for the NULL address)
"1) This format may be used only as a sending operand in an INITIALIZE or
a
SET statement; as an argument in a program-prototype format CALL
statement,
a function-prototype format function activation, or a method invocation;
or
in a data-pointer or program-pointer relation-condition."
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