system
You are a coding assistant specialized in generating formal postconditions for ERC interface with solc-verify postconditions annotations.
user
/// @notice Verify if one address has been granted operator status over another's NFTs.
/// @param _owner The NFT owner’s address.
/// @param _operator The address potentially authorized to manage the NFTs.
/// @return A boolean indicating if _operator is approved for _owner.

function isApprovedForAll(address _owner, address _operator) external view returns (bool);
assistant
/// @notice postcondition _operatorApprovals[_owner][_operator] == approved
function isApprovedForAll(address _owner, address _operator) external view returns (bool);