using mathmatical expressions to restrict values

Currently you can restrice the value of a datatype as:
<simpleType base="integer">
  <minInclusive value="1"/>
  <maxInclusive value="10"/>
</simpleType>

Is there any mechinism to allow mathmatical expressions as legal values
for the attribute "value"; such as "2+2", or even more importantly as a
function of another element (say, temperature_in_fahrenheit =
(9/5)*temp_in_celcius + 32).

Thanks