Circle with a slash through it at boot up

Hello and Happy New Year!
Yesterday morning I was greeted with the circle/slash image at boot up and my computer would not respond. I called the Protection Plan number and the guy walked me through safe-mode and selecting the start-up disk, etc and it worked. Again last night, the same thing - my iSight camera was not responding, so I did a restart and bam, no boot up. This morning, I walked through the same steps and it is again working.
What could be causing this? This is my first mac and I have been pleased with it so far, but this is annoying.
Thanks!!

Ok everyone following this discussion - here's the latest, and end hopefully, to my problem:
The prohibitory sign issue was solved by discovering another thread about how Norton for Mac does not uninstall everything unless you download a special uninstaller from their website (which is ridiculously hard to find - the link was in that thread). That solved the prohibitory sign.
However, the reason I had to keep restarting my computer was because CDs/DVDs would stop being recognized by the computer. Not found in iTunes, Desktop or Finder. Because of this, I would have to restart while holding the mouse button in order to force eject. I would import a couple cd's and then the next one would not be recognized.
Next step from Apple Care was to do a complete Erase and Install. I did. Surprisingly easy to do and much less painful than windows. AppleCare walked me through all the steps and I give them credit to their understanding and patience.
After the erase and install, i was told to not install ANY software and just import CDs. Well I had to install office 2008 because I had work to do, but if Office was causing the issues, there would be many more people calling and complaining.
SO - I call back the tech support gentleman that I had the extension of and he said that since this has happened within 30 days, they could give me a brand new computer replacement or replace the SuperDrive as they believe that is the hardware that is malfunctioning. I definitely chose for the replacement computer as, although this works fine otherwise, I have had the prohibitory sign and CDs/DVDs not recognized and would feel better having a fresh machine to start from.
All my fellow Mac owners say that this is a extremely rare scenario. Nonetheless it has happened on my first Mac and I sincerely hope it never does again. I want to like the Mac. I enjoy it when it is working - I like the machine itself. So hopefully, since besides Office 2008 this was a brand new machine after the reinstall, that I will have a much more pleasant experience with the new laptop.
So for those of you looking for an answer to the prohibitory sign - all that I can say is "have you installed and uninstalled Norton" or "do you have a VPN"? Both of those causes seemed to give me that issue.
I hope that someone eventually finds this solution helpful - I guess the solution is that the SuperDrive is faulty and that Norton and my VPN was causing the boot up to go haywire.
Oh - so if you have to erase and install..Time Machine works amazingly well. I was dumbfounded how easy it was to reinstall office. I downloaded Office 2008 from my university and only had 1 download allowed. Time Machine backed it up and all i did was 1) enter Time Machine, 2) Find my back up, 3) Click the Office 2008 application 4) click Restore. Done. Bam. Awesome!
Ok have a good one - and good luck! Big shout out to Apple Care and the support tech's who have helped me - everyone has been amazing!!

Similar Messages

My Mac Pro tower quad core crashed and is showing a NO sign (the circle with a slash through it). How do I safely get it to come back up ? Model A1186

My Mac Pro tower quad core crashed and is showing a NO sign (the circle with a slash through it). How do I safely get it to come back up ? Model A1186

General purpose Mac troubleshooting guide:
Isolating issues in Mac OS X
Creating a temporary user to isolate user-specific problems:
Isolating an issue by using another user account
Identifying resource hogs and other tips:
Using Activity Monitor to read System Memory and determine how much RAM is being used
Starting the computer in "safe mode":
Mac OS X: What is Safe Boot, Safe Mode?
To identify potential hardware problems:
Apple Hardware Test
General Mac maintenance:
Tips to keep your Mac in top form
Troubleshooting: My computer won't turn on
https://support.apple.com/kb/TS1367
Where are your bootable backups and clones stored?
What do you have to boot from to restore or attempt to recovery files that are not backed up?
It won't be a PowerMac. People tend to think they look alike? or mean the same thing.
http://www.everymac.com/systems/apple/mac_pro/specs/mac-pro-quad-2.66-specs.html
Try zap PRAM and SMC Reset. If you have ATI 5770 which many have upgraded to you won't be able to use older DVD or systems than 10.6.5

Sometimes on a re-start I get the apple logo then a circle with a slash through it.

Hello all! I have a 2010 Mac Pro sometimes on a re-start I will have the apple logo then it changes to a circle with a slash through it, the circle stays for awhile then eventually it does boot into the desktop, is there an issue going on that I need to address? Thanks in advance. Carl

Mac OS X: "Broken folder" icon, prohibitory sign, or kernel panic when computer starts

I get a red circle with a slash through it when trying to move music into folders.

I had to reformat my laptop hard drive. I moved everything to an external hard drive, and then brought it back after the reformat. I did something wrong, so all the folders are gone. I can create new playlist folders now, but when I try to move the music over, as soon as I get in the area with the playlist folders, it gives me the red circle with the slash through it, and stops me form dropping the songs in the folders.
I am logged into my account and the computer is authorized to my iTunes. Not sure where to go from here, other than the Apple store.

iTunes doesn't pay much attention to file and folder names with one minor exception. On import any untagged files will be given their filename as their track name.
You can drag a folder full of files onto a playlist and all the tracks will be added to the playlist, having first been added to the library if iTunes isn't already aware of them.
When you add files to iTunes from outside the iTunes Media folder and the option Copy files to iTunes Media folder when adding to library is enabled then copies will be created, and iTunes connected to those. If you subsequently import the same folder you will create duplicate files. If your files start life inside the iTunes Media folder, or that option is disabled, then they can be imported again without creating duplicates. However, if your files start life inside the iTunes Media folder and the option Keep iTunes Media folder organised is enabled, then once you have added the folder to the library the files inside it will probably be rearranged.
In the long term your library will be easier to maintain if all the files are inside the iTunes Media folder. It is probably easier to let iTunes manage them unless you are really particular about the layout or are importing files without tags such as wav, in which case I have some scripts that can extract useful information about the file from the filename and path provided iTunes doesn't get to throw it away first.
If your main aim is to rebuild some existing playlists, which exist by dint of all the files for each playlist being in separate folders, and you want to avoid creating duplicates, then try this.
Create a new empty playlist, select the music folder and put it into date added order.
Move all the files into the Automatically add to iTunes folder.
Select all the recently imported files, drag and drop them onto the new playlist.
Repeat until all files are added
tt2

Circle with a Slash Through it and Non-Mounting Hard Drive

Hello,
So I have a Macbook Pro (Early 2011) and the other day it was installing some update. It turned off, so I went upstairs to plug it in but once I powered it on and logged in it just shows a circle with a slash on it. The guest user account works fine. After researching on Google, I found out that the circle with slash means its missing boot files and I should try reinstalling the os with an archive and install. It wouldn't show up as a valid partition to recover from. In disk utility, the main hard drive shows up, the Macintosh HD shows up as well but is greyed out and will not mount. I just need to copy the files off it, and then I can do a clean install of the OS.
This is what I get when I try to repair the main hard drive from disk utility:
Verifying and repairing partition map for “Seagate FreeAgent Media”
Checking prerequisites
Checking the partition list
Checking for an EFI system partition
Checking the EFI system partition’s size
Checking the EFI system partition’s file system
Checking all HFS data partition loader spaces
Reviewing boot support loaders
Checking Core Storage Physical Volume partitions
Checking storage system
Checking volume.
disk3s2: Scan for Volume Headers
disk3s2: Scan for Disk Labels
Logical Volume Group C948DC54-AFC3-4E89-81C5-518FEBD8E2AB spans 1 device
Logical Volume Group has a 16 MB Metadata Volume with double redundancy
Start scanning metadata for a valid checkpoint
Load and verify Segment Headers
Load and verify Checkpoint Payload
Load and verify Transaction Segment
Load and verify Transaction Segment
Incorporate 1 newer non-checkpoint transactions
Load and verify Virtual Address Table
Load and verify Segment Usage Table
Unable to bootstrap transaction group 3803: inconsistent crosscheck
Continue scanning metadata for an older checkpoint
Load and verify Segment Headers
Load and verify Checkpoint Payload
Load and verify Transaction Segment
Incorporate 0 newer non-checkpoint transactions
Load and verify Virtual Address Table
Load and verify Segment Usage Table
Unable to bootstrap transaction group 3802: inconsistent crosscheck
Continue scanning metadata for an older checkpoint
Load and verify Segment Headers
Load and verify Checkpoint Payload
Load and verify Transaction Segment
Incorporate 0 newer non-checkpoint transactions
Load and verify Virtual Address Table
Load and verify Segment Usage Table
Unable to bootstrap transaction group 3801: inconsistent crosscheck
Continue scanning metadata for an older checkpoint
Load and verify Segment Headers
Load and verify Checkpoint Payload
Load and verify Transaction Segment
Incorporate 0 newer non-checkpoint transactions
Load and verify Virtual Address Table
Load and verify Segment Usage Table
Unable to bootstrap transaction group 3800: inconsistent crosscheck
No valid commit checkpoint found
The volume C948DC54-AFC3-4E89-81C5-518FEBD8E2AB was found corrupt and can not be repaired.
Problems were encountered during repair of the partition map
Error: Storage system verify or repair failed.
Also, I tried disk warrior but it doesn't show up as one of the drives available to repair. I'm running Lion on my machine.
Any ideas?? Thanks in advance.

SokrMan wrote:
The volume C948DC54-AFC3-4E89-81C5-518FEBD8E2AB was found corrupt and can not be repaired.
Problems were encountered during repair of the partition map
First off, thanks for being so detailed it saves a lot of trouble.
What has occured is your GUID partition map has become corrupted, this small hidden section on the drive is responsible for telling the hardware what and sizes of the partitions are on that drive. (OS X Lion, Lion Recovery and EFI)
The only way to rebuild the partition map is to erase and reformat the ENTIRE drive, including the hidden Lion Recovery Partition (which you booted into (Command R) to use Disk Utility to try to repair the drive.) Obviously this can't be done from the same drive booted from.
Unfortunatly with OS X 10.7 Apple didn't provide OS X install disks to install OS X onto a external drive or to boot from to perform the complete erase and reformat of the entire drive.
However if you have a blank powered external drive and a fast, reliable Internet connection (AppleID and password), you can Command R boot into Lion Recovery, format the external drive (Disk Utility: Partition: Options: GUID, Format: OS X Ext. J) and then install Lion from Apple's servers onto the external drive.
Once you have that, reboot holding the Option key down (wired keyboard) and select the external drive to boot from. Once you go through setup, try to grab your files off the internal drive.
(DataRescue can be used to recover deleted or corrupt file structure files directly from the 1's and 0's on the drive itself, it's $99, but a option if for some reason you can't do it manually via drag and drop)
Once you have all your files off the machine (make another copy to another drive and disconnect that drive), use Disk Utility (booted on the external drive, it's in the Utilities folder) to select the entire internal drive (drive makers name and size) and perform a Erase with Security Option Zero All Data. This will take a few hours so wait it out. What this will do is force 0's to every bit on the drive, if the hardware detects a bad sector it will map that bad sector off. (I suspect you have a failed sector in your GUID parititon map.)
Once that's complete, check the Partition tab: that Options is GUID and Format is OS X Extended (j)
Now if you have a newer Mac, if you reboot normally (no external drive connected) the Mac itself should install either the Lion Recovery Partition or combined with OS X all by itself over the Internet, I haven't seen or done this yet, so you'll be poineering this aspect. If you get Lion Recovery, then simply boot into it (Command R) and install Lion onto the Lion Partition.
Then go about installing all your apps first, then create a same named user as the old one (different password is fine) if you didn't use the same name as before, and then connect the external drive and transfer your contents of your User file folders (Music, Pictures, Movies etc) into their same name folders on the new setup, don't change anything, just select all and drag and drop, replace. By using the same user name, it preserves your itunes playlists and other data that depends upon correct user pathnames to the secondary files. If you start moving things around you'll lose the pathnames to your secondary files (songs). If your permissions are off, Finder: Get Info to set all (including down inside folders) to your new username.
If Internet Recovery doesn't work, option boot from the external drive and download Carbon Copy Cloner (free to use, donations accepted) and learn how to clone both your Lion Recovery Partition and OS X Lion Partition back onto your internal drive.
http://www.bombich.com/
https://support.apple.com/kb/HT4718
If by some chance you don't have a fast, relaible Internet connection your going to have ot take your machine to someplace that does, or have Apple fix the mess they caused by not supplying boot disks.
You can opt to buy the $69 Lion USB thumb drive, you can option boot off of that and perform the same functions above onto a external drive to boot from and recover your files.

Reset PRAM, now monitor shows just a circle with a slash through it

Big problem. My iBook clamshell has a battery that just started sometimes charging and sometimes uncharging while computer was plugged into power adapter. Then the computer just "blacked out" a few times while plugged into power adapter.
I bought a new power adapter, but still had the problem with the uncharging battery. One time the percentage amount of a charge would go down when it was being used while plugged into power adapter, the next time I used it the percentage amount might go back up to 100%. Money's really tight (I'm working part time & paying for emergency medical expenses) so instead of buying a new battery I dug out some instructions that helped my other clamshell that started "blacking out" a couple of years ago. At that time I was given a link to an article on resetting PRAM, and I'd printed out and kept the article.
While the iBook was starting up I held down the keys: Command, Option, P and R. You're supposed to hold down the keys until you heard the start up sound a 2nd time. Well, I messed up and held them down until I heard the start up sound 3 times. Maybe that was a fatal error - something screwed things up.
The monitor went from black to pale blue, but instead of getting the Apple icon as start up began I got a circle with a slash line through it. Nothing else happened. I had that circle mark for about 15 minutes - the computer never went into sleep mood and finally I improperly turned it off by using the power button.
I turned the computer on again, hoping the problem had gone away. I got the pale blue screen showing the circle with a slash mark. I waited awhile, thinking something might start happening after a delay. And once again I improperly turned the computer off using the power key. I won't turn it on again unless I'm given a possible solution.
I bought this 2nd iBook because it had an Airport card, and I take it to the library to use free WiFi. I've been entering an important manuscript that I don't want to use.
Is this fixable? This has me big-time frightened.

Hi Karen,
If your computer is back from the dead, then possibly your kernel panic issue has been resolved. Maybe there were software or directory issues that are now fixed.
It wouldn't hurt to go ahead and open Disk Utility and repair permissions. Disk Utility should be in the Utilities folder in your applications folder.
Repairing permissions is something you should do after every software download because permissions are changed for the download process. You repair permissions on the First Aid tab, and you want to repair them several times until there is nothing left to repair. While in Disk utility, you can also verify your hard drive and check the SMART status and make sure it doesn't have any problems. I would recommend you leave Disk Utility in the Dock so it will be handy next time you need it.
As long as your hard drive is in good shape, it won't have hurt anything to have skipped the step of verifying the drive. However, it is prudent to check on the hard drive before downloading software, because if the hard drive is failing or something, your priority will be to save the data off of it. A failing drive is unpredictable, and puts you at risk of losing everything. If you elect to keep Disk Utility in your Dock, you can check your drive anytime you like.
You can also do a Safe Boot as a maintenance item every so often:
http://support.apple.com/kb/HT1564?viewlocale=en_US
http://support.apple.com/kb/HT1455?viewlocale=en_US
http://support.apple.com/kb/TS1884?viewlocale=en_US
It sounds like maybe you reinstalled the OS by doing an Archive and Install, which would have installed a fresh copy of the OS while preserving all your settings and data.
Not sure why you can't connect to the internet. First check to be sure your airport card is plugged in and recognized. If it is, you should be able to go to System Preferences>Network and use the assistant to help you to reconnect. It may be you'd have to set up a new location or something like that.
One thing you should do is to put in place a backup strategy. If an external hard drive is beyond your means right now, at least try to find a USB flash drive. Office depot has 4 GB drives on sale for around $10 every so often, and you can find even better deals on line. You can store a lot of documents in 4 GB flash drive, and you would not have the worry of potentially losing everything if your computer dies. I am really glad you got your document back after all the hundreds of hours it took to create it, but there was a real danger that you could have lost it and all your other data.
Once you get your flash drive, use Disk Utility to format it (they usually come pre-formatted for Windows). You want to do this on the Partition tab--select Mac OS X Extended (Journaled) for the format and "Apple Partition Map" for the partition map scheme. You can also give your flash drive a name. Once you have it set up, you can mount it on your desktop and copy your documents etc. by dragging and dropping.
Good luck, and happy computing!

I downloaded the newest version and there is a Circle with a slash through it over the firefox icon. When I click on it the message is the system does not support this version. How do I reinstall the previous version?

I updated firefox. When I did there was a circle with a slash (as in No!) across the firefox icon. I clicked on it to open the browser and the error message reads: the application firefox cannot be launched - 10661
How do I go to the previous version that worked just fine?

Firefox 3.6.x is the last available from Mozilla for PPC Macs. 
http://www.mozilla.com/en-US/firefox/all-older.html
For older Macs that aren't supported in Firefox 4+ versions, try TenFourFox for PowerPC's running Mac 10.4.11 & 10.5.8 . 
http://www.floodgap.com/software/tenfourfox/ 
http://tenfourfox.blogspot.com/ 
https://code.google.com/p/tenfourfox/wiki/PluginsNoLongerSupported

My mac is showing a circle with a line through it on boot up any ideas

I have been having a couple of problems with my imac and it said to do a clean install so i then copied an image of my hard drive and followed the instructions such as delete and formate the disc and then reboot the system with the setup disc in it i then did this and followed the instructions but i then came back to the system to find it had powered off for some reason so i then tried to reboot it and the apple in the middle of the screen then changes to a circle with a line through it has anybody got any ideas or do i think the worst and look for a new hard drive oh i forgot to mension it will not eject the setup disc!!!!

It sounds like your hard disk is not accessible, I would first you need to start your iMac with the system DVD that came with your system, then format the hard drive with disk utility, then install the Mac OS X on to your newly formatted drive.

I have tried replacing the Firefox start-up page with my own home page choice many times and it will not set--I get the circle with the slash through it when I try to drag the webpage icon to "home."

I am using Windows 7 Professional, and have tried all of the recommended troubleshooting tips for this problem. I do not have the new version of Firefox installed because it had all kinds of problems so I went back to the version I had--I believe it was 3.6.24. Since then, I have not been able to set a home page. Any help out there? Thank You!

Try to drag the tab or the website's favicon on the Home button if you currently drag selected text.
If it doesn't work with dragging the icon then copy the URL to the clipboard and paste it via the Options window in the home page field.
*Tools > Options > General > Startup: Home page
Start Firefox in [[Safe Mode]] to check if one of the extensions or if hardware acceleration is causing the problem (switch to the DEFAULT theme: Firefox (Tools) > Add-ons > Appearance/Themes).
*Don't make any changes on the Safe mode start window.
*https://support.mozilla.com/kb/Safe+Mode

What does it mean when all I see on the screen is a circle with a slash?

I did a hard shutdown when my MacBookPro was not responding to a Save command, When I rebooted all I got was a circle with a slash through it in the center of the screen, and the "spinning wheel of death" below it. What happened??

Mac OS X: Gray screen appears during startup
What exact MacBook Pro and what Mac OS X version do you use, since the signature only states the name and the iOS version of your iPhone or iPad?

Update to 10.5.7 failed---Circle with slash through it when booting up.

Hi all. Looking for a little help/advice. I updated to 10.5.7 last night through software update. It downloaded fine...When I went to install, however, a message popped up (in several languages) telling me to shut down using the power button. Now whenever I turn the computer on, I get the gray apple and spinning wheel for about a minute before the circle with the slash replaces it. And then, nothing. I have tried to start in safe mode, reset the PRAM...Nothing seems to be working. Any advice out there before I have to call Apple?
Thanks in advance.

I think the GP poster meant that he has trouble booting from DVDs because the optical drive is going south.
If you're getting a circle with a slash, I think that either means that the kernel wasn't installed correctly and/or the drive wasn't blessed after the kernel was replaced. If you can boot the Mac OS X install DVD, run disk utility to fix any drive corruption, then do the "startup disk" thing on the install DVD, change the default startup disk to the install DVD and then change it back to your HD. This should rebless the right file in /System/Library/CoreServices or wherever it lives nowadays. If none of that helps... then you'll need to get a copy of the kernel and the bootloader off a working Mac OS X 10.5.7 install (or just reinstall the OS).

Will only boot to a circle with a slash

MacBook Pro will only boot to the circle with a slash symbol. I have tried all the turn on hold C, X, Option key suggestions and have tried the clearing ideas (hold cntl, commmd, p, r). Have put the system disk in to boot from that, now I cannot get the disk out.
Any suggestions out there?

Your computer is not recognizing your hard drive. Plug a mouse in and hold the mouse key down when booting. The disc should eject. Next, make sure the disc is real clean with no finger prints or scratches on it. Then try booting from it again (by holding the "C" key down) when booting. See if your Disk Utility sees the drive and run that. If it does not, or the unit will not boot from the install disc, then you have a serious problem--possibly logic board-related. You could also try running DiskWarrior and see if that will boot and repair the drive.
Dave M.
MacOSG Founder/Ambassador  An Apple User Group  iTunes: MacOSG

HD not booting. Circle with a cross through it

Hi Everyone.
I was getting an issue with system prefs and opted to restart my MBP.
After the start up sound, for a split second it showed the Apple logo followed by a circle with a cross through it.
Then it proceeded to boot up on my BootCamp windows partition. So I know the HD is working.
So, I started up the MBP with an external firewire drive that had an older complete copy of my drive from my OEM 500GB HD before my upgrade to a new 1TB drive. Then I ran Disk Utilities, verified that the Drive was OK, ran repair disk permissions and then did a Directory reconstruction with DiskWarrior. I hoped that all of the above would fix the problem. Alas, it is still not booting up from the 1TB drive.
With the external boot, I can see everything on the internal drive ok. I thought it may have been a resource fork, but I don't know now.
Anyone have any suggestions of what else I should look for?
My last resort will be to wipe the drive and rebuild from Time Machine, but a month has passed since my last back up ( so some stuff may be missed out).

If you want to see if you can recover data, see my FAQ*:
http://www.macmaps.com/backup.html#RECOVER
The fact that Disk Warrior can't fix the system folder, means there is serious file corruption, which may be as a result of all the issues with your System Preferences.
If you were using any other system optimization software, any that clean system caches should be avoided. They can make System Preferences and the rest of the system misbehave because corrupted system cache files can make applications have a hard time starting up.

The apple on the gray start-up screen turns into a circle with a slash.

My G5 has been pretty reliable for the past three (?) years. Lately it's been a bit squirrely booting up--once it went into kernel panic during boot, but powering down and restarting seemed to fix that. Lately, too, when I let the machine run and it goes to sleep I'll come back after a couple of hours to find the fan running at top speed and the machine unresponsive. Yesterday it seemed to have problems booting so I reset the PRAM and NVRAM and ran Onyx and it worked fine all day. This morning when I went to boot, I got the usual gray screen with the whirling gear. After about a minute, the apple in the center of the screen turned into a circle with a slash while the gear continued to whirl. How do I fix this?

I've subsequently tried a number of things. I reset the SMU, which didn't help until I also reset the PRAM. Computer booted normally. I rebooted from the Tiger DVD and repaired the start up disk; there were only two small errors to be fixed. The machine booted normally (and pretty quickly) for about a week before the problem resurfaced. I again went through the first two steps and got things working once more.
Lately the problem has returned. First, resetting the PRAM didn't help; only resetting the SMU worked. At the last event I needed to reset the PRAM without resetting the SMU. When I get home tonight I'll try booting from the DVD and repairing the permissions on the start up drive.
At first, I thought I'd leave it running all night, but when I got to the office in the morning the fans were running at full throttle and the machine was in a coma. All I could do was reboot--which it did, immediately going into kernel panic. I shut it down and rebooted, resetting the PRAM in the process. The computer booted and ran fine all day, although it seems slow (I did have Photoshop CS4 and Lightroom running simultaneously, but I do have 5 GB of RAM).
It's been suggested I may have a corrupt RAM chip (computer doesn't chirp at me, as I'm told it would) or, more terrifying, a processor is about to check out. I also have an ATTO SCSI card in this to run a legacy scanner. Could that be a problem?
Any advice?
JP

Mavericks Circle With a Slash

Just randomly today my macbook booted up with a circle and a slash through it. It hasn't happened before and from the other forums this usually only happens to new installations and my computer has had mavericks since October. I even used it this morning. I opened it up and the screen was frozen for two minutes so I rebooted it and when it started up, the circle and slash appeared. Please help!

Gray screen at startup
http://support.apple.com/kb/PH14062
Startup in Safe Mode
http://support.apple.com/kb/PH14204?viewlocale=en_US
Repair Disk.
Steps 1 through 7
http://support.apple.com/kb/PH5836
Reset PRAM
http://support.apple.com/kb/ph14222
Reinstall OS X
http://support.apple.com/kb/PH13871

Circle with a slash through it at boot up

Similar Messages

Maybe you are looking for