Question on 'above

Hello Everyone,

Sorry if this forum in not the right place to ask this question, but I
am not
sure where else I could ask it.  Does the LRM specify how simulators
should
handle the following wait statement:

    TestAbove : process is
    begin
      Count <= Count + 1;
      wait on SomeRealQuantity'above(SomeRealSignal);
    end process TestAbove;

when there is another process that can change the value of
SomeRealSignal?

For example, let's assume that when this process stops on the wait
statement,
the value of SomeRealSignal is 1.0 and the value of SomeRealQuantity is
0.0,
therefore the 'above returns a FALSE.  For simplicity, let's also assume
that
the quantity SomeRealQuantity is not changing.  Some time later another 
process decides to change the value of SomeRealSignal to -1.0.  Is this
change supposed to cause the 'above statement change to TRUE and get the
waiting process out of wait, or should it remain false until the
quantity
goes below and above the signal's new value?  In other words, is the
'above
attribute supposed to act on both its argument and quantity in "real
time",
or only on the quantity?

If you haven't guessed it yet, the reason I am asking this is because
two
different vendor's tools give me different results because of this.

Thanks,

Arpad
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