To compile routines capable of being passed as arguments to the I6 library routine for looping over parser scope at run-time, and so to provide an implementation for conditions such as "in the presence of Mrs Dalloway".

§1. Definitions. 

typedef struct loop_over_scope {
    struct parse_node *what_to_find;
    struct inter_name *los_iname;
    CLASS_DEFINITION
} loop_over_scope;

§2. 

loop_over_scope *PL::Actions::ScopeLoops::new(parse_node *what) {
    loop_over_scope *los = CREATE(loop_over_scope);
    los->what_to_find = Node::duplicate(what);
    if (Specifications::is_description(what)) {
        los->what_to_find->down = Node::duplicate(los->what_to_find->down);
        Descriptions::clear_calling(los->what_to_find);
    }
    package_request *PR = Hierarchy::local_package(LOOP_OVER_SCOPES_HAP);
    los->los_iname = Hierarchy::make_iname_in(LOOP_OVER_SCOPE_FN_HL, PR);
    return los;
}

loop_over_scope *latest_los = NULL;
int PL::Actions::ScopeLoops::compilation_coroutine(void) {
    int N = 0;
    while (TRUE) {
        loop_over_scope *los;
        if (latest_los == NULL)
            los = FIRST_OBJECT(loop_over_scope);
        else los = NEXT_OBJECT(latest_los, loop_over_scope);
        if (los == NULL) break;
        latest_los = los;
        Compile an individual loop-over-scope2.1;
        N++;
    }
    return N;
}

§2.1. Compile an individual loop-over-scope2.1 = 

    packaging_state save = Routines::begin(los->los_iname);

    ph_stack_frame *phsf = Frames::current_stack_frame();
    local_variable *it_lv = LocalVariables::add_pronoun(phsf, EMPTY_WORDING, K_object);
    inter_symbol *it_s = LocalVariables::declare_this(it_lv, FALSE, 8);

    Produce::inv_primitive(Emit::tree(), IF_BIP);
    Produce::down(Emit::tree());
        LocalVariables::begin_condition_emit();
        value_holster VH = Holsters::new(INTER_VAL_VHMODE);
        if (los->what_to_find) {
            parse_node *lv_sp = Lvalues::new_LOCAL_VARIABLE(EMPTY_WORDING, it_lv);
            PL::Actions::Patterns::compile_pattern_match_clause_inner(FALSE, &VH,
                lv_sp, FALSE, los->what_to_find, K_object, FALSE);
        } else
            Produce::val(Emit::tree(), K_truth_state, LITERAL_IVAL, 0);
        LocalVariables::end_condition_emit();
        Produce::code(Emit::tree());
        Produce::down(Emit::tree());
            Produce::inv_primitive(Emit::tree(), STORE_BIP);
            Produce::down(Emit::tree());
                Produce::ref_iname(Emit::tree(), K_value, Hierarchy::find(LOS_RV_HL));
                Produce::val_symbol(Emit::tree(), K_value, it_s);
            Produce::up(Emit::tree());
        Produce::up(Emit::tree());
    Produce::up(Emit::tree());
    Routines::end(save);