is_sexp new->process_quoted(to_sexp '()'), '(LIST 0)', 'process_quoted ()';
is_sexp new->process_quoted(to_sexp '(5 foo)'), '(LIST (LIST (LIST 0) (SYMBOL 3)) (SYMBOL 4))', 'process_quoted (5 foo)';
is_sexp new->process_quoted(to_sexp '(((5)))'), '(LIST (LIST 0) (LIST (LIST 0) (LIST (LIST 0) (SYMBOL 3))))', 'process_quoted (((5)))';
is_sexp new->process_quoted(to_sexp '()'), '(LIST 0)', 'process_quoted ()';
is_sexp new->process_quoted(to_sexp '(5 foo)'), '(LIST (LIST (LIST 0) (SYMBOL 3)) (SYMBOL 4))', 'process_quoted (5 foo)';
is_sexp new->process_quoted(to_sexp '(((5)))'), '(LIST (LIST 0) (LIST (LIST 0) (LIST (LIST 0) (SYMBOL 3))))', 'process_quoted (((5)))';