{"ast_node_type":"function","tokens":[{"end":81,"kind":"keyword","start":0,"text":"fn"}]}
    fn make_subtracted_sum(&mut self, lhs: CovTerm, rhs: &[CovTerm]) -> CovTerm {
    /// Creates a counter whose value is `lhs - SUM(rhs)`.
        let Some(rhs_sum) = self.make_sum(rhs) else { return lhs };