float / double values out of range - INF as closest value?

Hello

http://www.w3.org/TR/xmlschema-2/#float and similarly
http://www.w3.org/TR/xmlschema-2/#double
state that

"A literal in the *lexical space* representing a decimal number d maps
to the normalized value in the *value space*  of float that is closest
to d ..."

However, neither the spec nor the article by Clinger et al seem to state
explicitly how a 
value which exceeds the maximum possible value, e.g. 1E9999, is to be
approximated.

Should that value be rejected or is INF the closest value?

Best regards
Uli