The main documentation of the Character_Not_Equal_Status Procedure contains additional explanation of this code listing.
function Character_Not_Equal_Status (C, SS) result(Not_Equal) ! Input variable. type(Status_type), intent(in) :: SS ! Status variable to be compared. type(character,*), intent(in) :: C ! Selector flag string to be compared. ! Output variable. type(logical) :: Not_Equal ! Nonequality boolean. !~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ! Verify requirements. VERIFY(Valid_State(SS),1) ! SS is valid. ! Check nonequality. Not_Equal = status_flag(SS%status)%selector /= C ! Verify guarantees. ! Not_Equal should be what it was set to. VERIFY(Not_Equal .eqv. (status_flag(SS%status)%selector /= C),2) return end function Character_Not_Equal_Status