1. The first type is the addition of an action that is similar: 3. The third type is doubt

to the actions of the prayers such as adding a bowing or any pillar. The prayer would be invalidated if that was done intentionally, and if done absentmindedly he must prostrate for the forgetfulness. 2. The second type is omission, like forgetting a mandatory action

For every act of forgetfulness, two prostrations are prescribed before tasleem. The following three cases require the prostrations be done right after tasleem and then tasleem is made again, however if they are done before, it would be acceptable: