Logic sytem conforming with the principle of bivalence.

In this system possibilities are given a variable, or atomic formula. A well formed formula is defined thus:


	wff ::= wff connective wff
		| not(wff)
		| wff
		| atomic formula

	connective ::= and | or | implies | two-way implication

Implies is often written →
two-way implication is often written ↔
And is written ^
Or is written as an upside-down ^.

For example, the statement "If I am in a house, I am inside and off the streets" could be expressed as a well formed formula of propositional logic thusly: H -> (I ^ O)