proc print_environment(Environment*) -> void;
proc eval_arguments(Lisp_Object*, Environment*, int*) -> Lisp_Object*;
proc eval_expr(Lisp_Object*, Environment*) -> Lisp_Object*;
proc is_truthy (Lisp_Object*, Environment*) -> bool;
proc list_length(Lisp_Object*) -> int;
proc load_built_ins_into_environment(Environment*) -> void;
proc parse_argument_list(Lisp_Object*, Function*) -> void;