Rules that exist in many languages that force some parts of a sentence to be used or inflected differently depending on certain attributes of other parts.
A legally binding contract enforceable in a court of law.
An understanding between entities to follow a specific course of conduct.
A state whereby several parties share a view or opinion; the state of not contradicting one another.
Any contradiction or paradox.
In the thought of the German philosopher Immanuel Kant (1724–1804): an apparent contradiction between valid conclusions; a paradox.