Any contradiction or paradox.
In the thought of the German philosopher Immanuel Kant (1724–1804): an apparent contradiction between valid conclusions; a paradox.
The state of differing or being in conflict.
A discrepancy between two legal documents.
A departure from a cause of action originally in a complaint.
An official permit to do something that is ordinarily forbidden by regulations.
The act of varying or the state of being variable.
The number of degrees of freedom in a system.
Covariance and contravariance generally.
A difference between what is expected and what is observed; deviation.
The second central moment in probability.