λ x : word128 * word128,
Interp-η
(λ var : Syntax.base_type → Type,
 λ '(x1, x2)%core,
 uint128_t x3 = x2 | x1;
 return x3)
x
     : word128 * word128 → ReturnType (Tbase match (if match match (let (lower, _) := Synthesis.P.bound1 in
                                                                    lower) with
                                                             | 0%Z => Eq
                                                             | Z.pos _ => Lt
                                                             | Z.neg _ => Gt
                                                             end with
                                                       | Eq => true
                                                       | Lt => true
                                                       | Gt => false
                                                       end then Some 7 else None) with
                                             | Some lgsz => Syntax.TWord lgsz
                                             | None => Syntax.TZ
                                             end)