{"ast_node_type":"other","tokens":[{"end":114,"kind":"keyword","start":0,"text":"//!"}]}
//!         - We recursively compute `usefulness(specialize(c, tp_1) ... specialize(c, tp_n), specialize(c, tq))`,
//!     - For each such constructor `c` for which `specialize(c, tq)` is not nothing:
//!             where we discard any `specialize(c, p_i)` that returns nothing.