card : CARD ;
-- This feature returns the value of self as an unsigned exact number,
-- providing that self is an exact number value within the range
-- CARD::maxval to CARD::minval.
field : FIELD ;
-- This feature returns the value of self as a closed field number,
-- providing that self is an exact number value.
int : INT ;
-- This feature returns the value of self as a signed exact number,
-- providing that self is an exact number value and within the range
-- INT::maxval to INT::minval.
inti : INTI ;
-- This feature returns the value of self as an infinite precision
-- integer - rounded towards the nearest integral value.
rat : RAT ;
-- This feature returns the value of self as a rational number.
flt : FLT ;
-- This feature returns the value of self as a floating point number. If
-- the value is not representable as a floating point number then infinity
-- is to be returned.
fltd : FLTD ;
-- This feature returns the value of self as a double floating point
-- number. If the value is not representable then infinity is to be returned.