- is what inverts the time track, one wishes it hadn't happened and so he tries to collapse the track on the point. Actually overt acts collapse the track but the emotion of regret is experienced at that level. (5904C08)
- the action of trying to make time run backwards. (5206CM24E)
- simply an effort to take something out of the timestream, "I'm sorry it happened. I wish it hadn't happened." (5112CM29A)
- entirely the study of reversed postulates. One intended to do something good and one did something bad or one intended to do something bad and accidentally did something good. Either incident would be regretted. (PAB 91)