Some articles on rules:
... In natural deduction the flow of information is bi-directional elimination rules flow information downwards by deconstruction, and introduction rules flow ... In the sequent calculus all inference rules have a purely bottom-up reading ... Inference rules can apply to elements on both sides of the turnstile ...
Famous quotes containing the words rules and/or left:
“This was Pharaoh, direct descendent of our deity Amon, god of the sun, who rules the heavens as Pharaoh rules the earth. Again, he brought treasure, gold, and precious jewels taken from our enemies. For to Pharaoh riches were power and power was to be desired. And also again he brought many captives. For is it not by slaves that one becomes even richer and then has even more power?”
—William Faulkner (18971962)
“I am secretly afraid of animals.... I think it is because of the usness in their eyes, with the underlying not-usness which belies it, and is so tragic a reminder of the lost age when we human beings branched off and left them: left them to eternal inarticulateness and slavery. Why? their eyes seem to ask us.”
—Edith Wharton (18621937)