File: contracts/RubiconMarket.sol   #1

77:           z = add(mul(x, y), WAD / 2) / WAD;
File: contracts/RubiconMarket.sol   #2

81:           z = add(mul(x, y), RAY / 2) / RAY;
File: contracts/RubiconMarket.sol   #3

85:           z = add(mul(x, WAD), y / 2) / y;
File: contracts/RubiconMarket.sol   #4

89:           z = add(mul(x, RAY), y / 2) / y;
