λ x x0 : word64 * word64,
Interp-η
(λ var : Syntax.base_type → Type,
 λ '(x4, x5, (x6, x7))%core,
 uint64_t x9, uint8_t x10 = addcarryx_u64(0x0, x5, x7);
 uint64_t x12, uint8_t x13 = addcarryx_u64(x10, x4, x6);
 uint64_t x15, uint8_t x16 = subborrow_u64(0x0, x9, 0xffffffffffffffffL);
 uint64_t x18, uint8_t x19 = subborrow_u64(x16, x12, 0x7fffffffffffffffL);
 uint64_t _, uint8_t x22 = subborrow_u64(x19, x13, 0x0);
 uint64_t x23 = cmovznz64(x22, x18, x12);
 uint64_t x24 = cmovznz64(x22, x15, x9);
 return (x23, x24))
(x, x0)%core
     : word64 * word64 → word64 * word64 → ReturnType (uint64_t * uint64_t)