-# fun +=( other : A ) : A import value, value=, A `{
-# int new_val = A_value( recv ) + A_value( other );
-# A_value__assign( recv, new_val );
-# return new_A( new_val );
-# `}
-
-# fun -=( other : A ) : A import +=, A, value `{
-# A inv_other = new_A( -1*A_value( other ) );
-# return A__plus_equal( recv, int_other );
-# `}
-
- fun <=>( other : A ) : A import value, A `{