case NONNUMERIC :
// if this is modified, please modify the getArithmeticOperations
// in TypeChecker as well
ArithmeticOperations ops = getArithmeticOperations(v1Type, v2Type);
if (ops != null) {
return ops.substract(v1, v2);
}
return newReal( type, doubleValue(v1) - doubleValue(v2) );
case CUSTOMNUMERICTYPE:
ArithmeticOperations operations =
getArithmeticOperations(v1Type, v2Type);