{"ast_node_type":"other","tokens":[{"end":33,"kind":"keyword","start":0,"text":"(ReVar(_),"}]}
            (ReVar(_), _) => self
                .add_constraint(Constraint { kind: ConstraintKind::RegSubVar, sub, sup }, origin),
                .add_constraint(Constraint { kind: ConstraintKind::VarSubReg, sub, sup }, origin),