Every Solidity file specifies in the header a version number of the format `pragma solidity (^)0.4.*`. The caret (`^`) before the version number implies an unlocked pragma, meaning that the compiler will use the specified version _and above_, hence the term "unlocked". Different versions of Solidity is used: ``` - Version used: ['0.6.11', '>=0.4.24<0.8.0', '>=0.5.0', '>=0.6.0', '>=0.6.0<0.8.0', '>=0.6.2', '>=0.6.2<0.8.0', '^0.6.0', '^0.6.5'] - ^0.6.5 (node_modules/@0x/contracts-erc20/contracts/src/v06/IERC20TokenV06.sol#20) - ^0.6.5 (node_modules/@0x/contracts-utils/contracts/src/v06/LibSafeMathV06.sol#20) - ^0.6.5 (node_modules/@0x/contracts-utils/contracts/src/v06/errors/LibRichErrorsV06.sol#20) - ^0.6.5 (node_modules/@0x/contracts-utils/contracts/src/v06/errors/LibSafeMathRichErrorsV06.sol#20) - ^0.6.5 (node_modules/@0x/contracts-zero-ex/contracts/src/errors/LibNativeOrdersRichErrors.sol#20) - ^0.6.5 (node_modules/@0x/contracts-zero-ex/contracts/src/errors/LibSignatureRichErrors.sol#20) - ^0.6.5 (node_modules/@0x/contracts-zero-ex/contracts/src/features/interfaces/INativeOrdersEvents.sol#20) - ABIEncoderV2 (node_modules/@0x/contracts-zero-ex/contracts/src/features/interfaces/INativeOrdersEvents.sol#21) - ^0.6.5 (node_modules/@0x/contracts-zero-ex/contracts/src/features/interfaces/INativeOrdersFeature.sol#20) - ABIEncoderV2 (node_modules/@0x/contracts-zero-ex/contracts/src/features/interfaces/INativeOrdersFeature.sol#21) - ^0.6.5 (node_modules/@0x/contracts-zero-ex/contracts/src/features/libs/LibNativeOrder.sol#20) - ABIEncoderV2 (node_modules/@0x/contracts-zero-ex/contracts/src/features/libs/LibNativeOrder.sol#21) - ^0.6.5 (node_modules/@0x/contracts-zero-ex/contracts/src/features/libs/LibSignature.sol#20) - ABIEncoderV2 (node_modules/@0x/contracts-zero-ex/contracts/src/features/libs/LibSignature.sol#21) - >=0.6.0 (node_modules/@chainlink/contracts/src/v0.6/interfaces/AggregatorV3Interface.sol#2) - ^0.6.0 (node_modules/@gnosis.pm/mock-contract/contracts/MockContract.sol#1) - >=0.6.0<0.8.0 (node_modules/@openzeppelin/contracts-upgradeable/access/AccessControlUpgradeable.sol#3) - >=0.6.0<0.8.0 (node_modules/@openzeppelin/contracts-upgradeable/access/OwnableUpgradeable.sol#3) - >=0.6.0<0.8.0 (node_modules/@openzeppelin/contracts-upgradeable/math/MathUpgradeable.sol#3) - >=0.6.0<0.8.0 (node_modules/@openzeppelin/contracts-upgradeable/math/SafeMathUpgradeable.sol#3) - >=0.4.24<0.8.0 (node_modules/@openzeppelin/contracts-upgradeable/proxy/Initializable.sol#4) - >=0.6.0<0.8.0 (node_modules/@openzeppelin/contracts-upgradeable/token/ERC20/ERC20Upgradeable.sol#3) - >=0.6.0<0.8.0 (node_modules/@openzeppelin/contracts-upgradeable/token/ERC20/IERC20Upgradeable.sol#3) - >=0.6.0<0.8.0 (node_modules/@openzeppelin/contracts-upgradeable/token/ERC20/SafeERC20Upgradeable.sol#3) - >=0.6.2<0.8.0 (node_modules/@openzeppelin/contracts-upgradeable/utils/AddressUpgradeable.sol#3) - >=0.6.0<0.8.0 (node_modules/@openzeppelin/contracts-upgradeable/utils/ContextUpgradeable.sol#3) - >=0.6.0<0.8.0 (node_modules/@openzeppelin/contracts-upgradeable/utils/EnumerableSetUpgradeable.sol#3) - >=0.6.0<0.8.0 (node_modules/@openzeppelin/contracts-upgradeable/utils/PausableUpgradeable.sol#3) - >=0.6.0<0.8.0 (node_modules/@openzeppelin/contracts/access/AccessControl.sol#3) - >=0.6.0<0.8.0 (node_modules/@openzeppelin/contracts/access/Ownable.sol#3) - >=0.6.0<0.8.0 (node_modules/@openzeppelin/contracts/cryptography/ECDSA.sol#3) - >=0.6.0<0.8.0 (node_modules/@openzeppelin/contracts/cryptography/MerkleProof.sol#3) - >=0.6.0<0.8.0 (node_modules/@openzeppelin/contracts/math/Math.sol#3) - >=0.6.0<0.8.0 (node_modules/@openzeppelin/contracts/math/SafeMath.sol#3) - >=0.6.0<0.8.0 (node_modules/@openzeppelin/contracts/presets/ERC20PresetMinterPauser.sol#3) - >=0.6.0<0.8.0 (node_modules/@openzeppelin/contracts/token/ERC20/ERC20.sol#3) - >=0.6.0<0.8.0 (node_modules/@openzeppelin/contracts/token/ERC20/ERC20Burnable.sol#3) - >=0.6.0<0.8.0 (node_modules/@openzeppelin/contracts/token/ERC20/ERC20Pausable.sol#3) - >=0.6.0<0.8.0 (node_modules/@openzeppelin/contracts/token/ERC20/IERC20.sol#3) - >=0.6.0<0.8.0 (node_modules/@openzeppelin/contracts/token/ERC20/SafeERC20.sol#3) - >=0.6.2<0.8.0 (node_modules/@openzeppelin/contracts/utils/Address.sol#3) - >=0.6.0<0.8.0 (node_modules/@openzeppelin/contracts/utils/Context.sol#3) - >=0.6.0<0.8.0 (node_modules/@openzeppelin/contracts/utils/EnumerableSet.sol#3) - >=0.6.0<0.8.0 (node_modules/@openzeppelin/contracts/utils/Pausable.sol#3) - >=0.6.0<0.8.0 (node_modules/@openzeppelin/contracts/utils/SafeCast.sol#3) - >=0.5.0 (node_modules/@sushiswap/core/contracts/uniswapv2/interfaces/IUniswapV2ERC20.sol#3) - >=0.5.0 (node_modules/@sushiswap/core/contracts/uniswapv2/interfaces/IUniswapV2Factory.sol#3) - >=0.6.2 (node_modules/@sushiswap/core/contracts/uniswapv2/interfaces/IUniswapV2Router01.sol#3) - >=0.6.2 (node_modules/@sushiswap/core/contracts/uniswapv2/interfaces/IUniswapV2Router02