False (logic) - Wikipedia
en.wikipedia.org › wiki › False_(logic)False, negation and contradiction. In most logical systems, negation, material conditional and false are related as: ¬ p ⇔ (p → ⊥). In fact, this is the definition of negation in some systems, such as intuitionistic logic, and can be proven in propositional calculi where negation is a fundamental connective.
Atomic formula - Wikipedia
en.wikipedia.org › wiki › Atomic_formulaAtomic formula in first-order logic. The well-formed terms and propositions of ordinary first-order logic have the following syntax: . Terms: (, …,),that is, a term is recursively defined to be a constant c (a named object from the domain of discourse), or a variable x (ranging over the objects in the domain of discourse), or an n-ary function f whose arguments are terms t k.