In mathematics, a proof is a convincing demonstration (within the accepted standards of the field) that some mathematical statement is necessarily true. Proofs are obtained from deductive reasoning, rather than from inductive or empirical arguments. That is, a proof must demonstrate that a statement is true in all cases, without a single exception. An unproven proposition that is believed to be true is known as a conjecture.

The statement that is proved is often called a theorem. Once a theorem is proved, it can be used as the basis to prove further statements. A theorem may also be referred to as a lemma, especially if it is intended for use as a stepping stone in the proof of another theorem.

Proofs employ logic but usually include some amount of natural language which usually admits some ambiguity. In fact, the vast majority of proofs in written mathematics can be considered as applications of rigorous informal logic. Purely formal proofs, written in symbolic language instead of natural language, are considered in proof theory. The distinction between formal and informal proofs has led to much examination of current and historical mathematical practice, quasi-empiricism in mathematics, and so-called folk mathematics (in both senses of that term). The philosophy of mathematics is concerned with the role of language and logic in proofs, and mathematics as a language.

• People (5)
• Provability and Interpretability Logics@ (9)

• Science: Math: Logic and Foundations: Computational Logic: Automated Reasoning (1)

• G. Japaridze's Papers
  csc.villanova.edu
  Full list of publications by this author, with about 30 items in the area of proof theory. Many of the papers are downloadable.
• Linear Network
  iml.univ-mrs.fr
  Linear Logic in Computer Science is lead by the "Logic of Programming" research team. Its thematic is focused on developing the theory and the applications of Linear Logic. It is formed by seven sites located in Marseille, Bologna, Cambridge, Edinburgh, Lisboa, Paris and Roma, and a few subsites.
• Logic of programming
  iml.univ-mrs.fr
  The "Logic of Programming" research team is interested in proof theory and its relations with theoretical computer science. The main topic is mathematical interpretation of proofs : nets (proof = graph), denotational semantics (proof = function), and game semantics (proof = strategy). Two realisations of this working program are Linear Logic and Ludics.

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  Sun Feb 26 22:16:50 2012