De facto standard arithmetic constants missing

[pmoura]

It would be also quite useful to have the following de facto standard arithmetic constants available:

?- X is pi.
{ERROR: arithmetic:is/2, arg 2 - expected an arithmetically evaluable expression, found pi}

aborted
?- X is e.
{ERROR: arithmetic:is/2, arg 2 - expected an arithmetically evaluable expression, found e}

aborted
?- X is epsilon.
{ERROR: arithmetic:is/2, arg 2 - expected an arithmetically evaluable expression, found epsilon}

aborted