into logical symbols and non-logical symbols (sometimes also called logical and non-logical constants). The non-logical symbols of a language of first-order...

symbols Logic alphabet, a suggested set of logical symbols Logic gate § Symbols Logical connective Mathematical operators and symbols in Unicode Non-logical...

In logic, a logical constant or constant symbol of a language L {\displaystyle {\mathcal {L}}} is a symbol that has the same semantic value under every...

the extension { ( a ) } {\displaystyle \{(\mathrm {a} )\}} to the non-logical symbol T {\displaystyle T} , and does not make a claim about whether T {\displaystyle...

and computer science. First-order logic uses quantified variables over non-logical objects, and allows the use of sentences that contain variables. Rather...

the relation denoted by R {\displaystyle R} . Since predicates are non-logical symbols, they can denote different relations depending on the interpretation...

especially mathematical logic, a signature lists and describes the non-logical symbols of a formal language. In universal algebra, a signature lists the...

rarely used, see List of logic symbols. ¬    (not sign) Denotes logical negation, and is read as "not". If E is a logical predicate, ¬ E {\displaystyle...

unambiguous symbols. This allows logical statements to not be understood in an ambiguous way. These symbols are called logical connectives, logical operators...

then there is a formula ρ, called an interpolant, such that every non-logical symbol in ρ occurs both in φ and ψ, φ implies ρ, and ρ implies ψ. The theorem...

the symbol ¬ {\displaystyle \neg } signifies logical negation, ∨ {\displaystyle \lor } signifies OR, and ∧ {\displaystyle \land } signifies AND. Non-disjunction...

mathematical, logical, and set notation. The Supplemental Mathematical Operators block (U+2A00–U+2AFF) contains various mathematical symbols, including N-ary...

logic, disjunction (also known as logical disjunction, logical or, logical addition, or inclusive disjunction) is a logical connective typically notated as...

disjunction, exclusive alternation, logical non-equivalence, or logical inequality is a logical operator whose negation is the logical biconditional. With two inputs...

formal fallacy is a pattern of reasoning rendered invalid by a flaw in its logical structure. Propositional logic, for example, is concerned with the meanings...

often not clear how to distinguish formal from non-formal features, i.e. logical from non-logical symbols. This distinction lies at the very heart of the...

Logical truth is one of the most fundamental concepts in logic. Broadly speaking, a logical truth is a statement which is true regardless of the truth...

Non-logical axioms may also be called "postulates", "assumptions" or "proper axioms". In most cases, a non-logical axiom is simply a formal logical expression...

Logical consequence (also entailment or logical implication) is a fundamental concept in logic which describes the relationship between statements that...

{\displaystyle \mathbb {N} .} The non-logical symbols for the axioms consist of a constant symbol 0 and a unary function symbol S. The first axiom states that...

if it is ℵα-saturated. The countable random graph, with the only non-logical symbol being the edge existence relation, is also saturated, because any...

rendering support, you may see question marks, boxes, or other symbols. An arrow is a graphical symbol, such as ←, ↑ or →, or a pictogram, used to point or indicate...

used. However, these symbols are also used for material equivalence, so proper interpretation would depend on the context. Logical equivalence is different...

In mathematical logic and computer science the symbol ⊢ ( ⊢ {\displaystyle \vdash } ) has taken the name turnstile because of its resemblance to a typical...

other non-logical symbols, and a formula is said to be satisfiable if there is some interpretation which makes it true. While this allows non-standard...

A logical symbol is a fundamental concept in logic, tokens of which may be marks or a configuration of marks which form a particular pattern.[citation...

fallacies—invalid argument forms involving logical errors. Rules of inference belong to logical systems, and distinct logical systems use different rules of inference...

arithmetic. Just as in first-order logic, second-order logic may include non-logical symbols in a particular second-order language. These are restricted, however...

or language is a set of non-logical symbols such that each symbol is either a constant symbol, or a function or relation symbol with a specified arity...

depends on its logical form. In logic, an argument is a set of related statements expressing the premises (which may consists of non-empirical evidence...