{"ast_node_type":"variable","tokens":[{"end":82,"kind":"keyword","start":0,"text":"let"}]}
        let totally_ordered_subset = choice_regions.iter().copied().filter(|&r1| {
        // `['d, 'e]` are ignored because they do not compare - the same goes for `['a, 'b]`.
            choice_regions.iter().all(|&r2| {