Atom

Definition

Atom

An atom is the smallest building block of a logic’s formulas: a basic symbol that can be assigned a truth value. The precise notion depends on the order of the logic: propositional atoms are the basic propositional symbols, while in first-order logic the atoms are the atomic formulas $P(t_1,\dots ,t_n)$.

Propositional logic

Definition

Atom (Propositional Logic)

An atom (or propositional variable) is a basic propositional symbol such as $p,q,r$, to which an interpretation assigns a truth value.

Atoms are the base case of the formula grammar: they are formulas themselves, and every other formula is built from them by logical connectives.

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