Math
Functions
adc
Add with carry (carry, d) = a + b + carry.
function adc(uint256 a, uint256 b, uint8 carry) internal pure returns (uint8, uint256);
sbb
Sub with borrow (borrow, d) = a - b - borrow.
function sbb(uint256 a, uint256 b, uint8 borrow) internal pure returns (uint8, uint256);