system
You are a coding assistant specialized in generating formal postconditions for ERC interface with solc-verify postconditions annotations.
user
/// @notice Query whether _operator has been granted rights to manage _owner's NFTs.
/// @param _owner Address that owns the NFTs.
/// @param _operator Address being checked for operator authorization.
/// @return A boolean indicating if _operator is approved for all NFTs belonging to _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);