Laws
A law of Boolean algebra is an equation such as x∨(y∨z) = (x∨y)∨z between two Boolean terms, where a Boolean term is defined as an expression built up from variables and the constants 0 and 1 using the operations ∧, ∨, and ¬. The concept can be extended to terms involving other Boolean operations such as ⊕, →, and ≡, but such extensions are unnecessary for the purposes to which the laws are put. Such purposes include the definition of a Boolean algebra as any model of the Boolean laws, and as a means for deriving new laws from old as in the derivation of x∨(y∧z) = x∨(z∧y) from y∧z = z∧y as treated in the section on axiomatization.
Read more about this topic: Boolean Algebra
Famous quotes containing the word laws:
“I have not yet learned to live, that I can see, and I fear that I shall not very soon. I find, however, that in the long run things correspond to my original idea,—that they correspond to nothing else so much; and thus a man may really be a true prophet without any great exertion. The day is never so dark, nor the night even, but that the laws at least of light still prevail, and so may make it light in our minds if they are open to the truth.”
—Henry David Thoreau (1817–1862)
“It is dangerous to tell the people that the laws are unjust; for they obey them only because they think them just. Therefore it is necessary to tell them at the same time that they must obey them because they are laws, just as they must obey superiors, not because they are just, but because they are superiors. In this way all sedition is prevented.”
—Blaise Pascal (1623–1662)
“Always the laws of light are the same, but the modes and degrees of seeing vary.”
—Henry David Thoreau (1817–1862)