Re: language problem

[ROSENBLUM@SIERRA.STANFORD.EDU.UUCP]

I think that the LRM is pretty clear on this point.

4.5.6 (2) says that the "not" operator takes a value of
any array of boolean components, and returns a value of
the same array type.  The important words here are SAME TYPE.
3.6 (5) says that an array type is characterized by
a set of index types and a component subtype.  Thus,
in the example the value of "not A" must be a value of
the type of A, which is ARR.  Since the resulting component
values do not satisfy the component subtype constraint,
the result is NOT a value of type ARR.  Ergo, CONSTRAINT_ERROR
must be raised by the evaluation of "not A".  Note that
the fact that the expression appears in an array assignment
is not germane; the evaluation of such a "not A" in any context
should raise CONSTRAINT_ERROR.

-- David.
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