{"ast_node_type":"other","tokens":[{"end":92,"kind":"keyword","start":0,"text":"//"}]}
        // not actually looking into substitutions, just walking through fields / the "RHS".
        // First, check if the ADT/LTA is (probably) cyclical. We say probably here, since we're
        // We don't recurse into the hidden types of opaques or anything else fancy.