[PRD] class membership assertions

Hi,

I found a strange discrepancy in PRD. In the definition of assert fact
actions [1], it is possible to assert class membership facts.
Now, I understand that there is a shortcut syntax for asserts in the XML [2]
and presentation [3] syntaxes. In particular, it's not necessary to write
the "Assert" for positional and frame atoms. However, if one wants to assert
a class membership formula, one is required to write the "Assert".
Why is there this discrepancy? Was that an oversight?


Cheers, Jos

[1] http://www.w3.org/TR/2010/PR-rif-prd-20100511/#Actions_2
[2] http://www.w3.org/TR/2010/PR-rif-prd-20100511/#ACTION_BLOCK
[3]
http://www.w3.org/TR/2010/PR-rif-prd-20100511/#Presentation_syntax_.28Informative.29
-- 
Jos de Bruijn
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