λ x x0 : word128 * word128,
Interp-η
(λ var : Syntax.base_type → Type,
 λ '(x4, x5, (x6, x7))%core,
 uint128_t x9, uint8_t x10 = addcarryx_u128(0x0, x5, x7);
 uint128_t x12, uint8_t x13 = addcarryx_u128(x10, x4, x6);
 uint128_t x15, uint8_t x16 = subborrow_u128(0x0, x9, 0xffffffffffffffffffffffffL);
 uint128_t x18, uint8_t x19 = subborrow_u128(x16, x12, 0xffffffff000000010000000000000000L);
 uint128_t _, uint8_t x22 = subborrow_u128(x19, x13, 0x0);
 uint128_t x23 = cmovznz128(x22, x18, x12);
 uint128_t x24 = cmovznz128(x22, x15, x9);
 return (x23, x24))
(x, x0)%core
     : word128 * word128 → word128 * word128 → ReturnType (uint128_t * uint128_t)