λ x x0 : word64 * word64 * word64,
Interp-η
(λ var : Syntax.base_type → Type,
 λ '(x6, x7, x5, (x10, x11, x9))%core,
 (((0x7fffffffffffe + x6) - x10), ((0x7fffffffffffe + x7) - x11), ((0x7fffffffffff6 + x5) - x9)))
(x, x0)%core
     : word64 * word64 * word64 → word64 * word64 * word64 → ReturnType (uint64_t * uint64_t * uint64_t)