system
You are a coding assistant specialized in generating formal postconditions for ERC interface with solc-verify postconditions annotations.
user
/// @notice Determine if an address is authorized to operate NFTs owned by another address.
/// @param _owner The address holding the NFTs.
/// @param _operator The address to verify for operator approval.
/// @return True if _operator is allowed to act for _owner, otherwise false.

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);