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From: "Jeffrey R. Carter" <spam.jrcarter.not@spam.not.acm.org>
Newsgroups: comp.lang.ada
Subject: Re: quantified expression with empty array?
Date: Fri, 9 Mar 2018 19:40:50 +0100
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Date: 2018-03-09T19:40:50+01:00
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On 03/09/2018 06:15 PM, Stephen Leake wrote:
> I ran across this question recently:
> 
> If I have a quantified expression:
> 
>    (for some Child of Children => Predicate (Child))
> 
> what is the value if Children'Length = 0?

4.5.8(9) reads, "If the quantifier is some, the expression is True if the 
evaluation of any predicate yields True; evaluation of the quantified_expression 
stops at that point. Otherwise (every predicate has been evaluated and yielded 
False), the expression is False." As we all learned in school, a parenthetical 
expression can be discarded without changing the meaning, so this is equivalent 
to "If the quantifier is some, the expression is True if the evaluation of any 
predicate yields True; evaluation of the quantified_expression stops at that 
point. Otherwise, the expression is False."

Since no predicate evaluated to True, the expression is False.

-- 
Jeff Carter
"To Err is human, to really screw up, you need C++!"
Stéphane Richard
63