Proof theorists

Proof theory is a branch of mathematical logic that focuses on the study of formal proofs and the structure of mathematical statements. It investigates the nature of proofs, the principles that govern them, and the relationships between different proof systems. Proof theorists analyze various logical systems, including propositional and predicate logic, to understand the properties of proofs, such as consistency, completeness, and decidability.

As of my last knowledge update in October 2021, Dick de Jongh may refer to a person, but there isn't specific or widely recognized information about an individual by that name in popular culture, sports, or other public domains.

Gaisi Takeuti was a prominent Japanese mathematician known for his work in mathematical logic and proof theory. He made significant contributions to the field, particularly in the area of constructive mathematics and the foundations of mathematics. Takeuti is well-known for his development of the so-called "Takeuti's theorem" concerning the relationships among different systems of logic and his works on the theory of formal systems.

Jacques Herbrand was a French mathematician and logician, known for his significant contributions to mathematical logic, particularly in the areas of proof theory, model theory, and the foundations of mathematics. He was born on December 20, 1908, and died tragically young at the age of 27 in a car accident in 1931. Herbrand is especially recognized for Herbrand's theorem and Herbrand's universes, which are crucial in the context of first-order logic.

Jan Śleszyński could refer to a person or a historical figure, but there might be limited widely-known information about someone by that name. If Jan Śleszyński is a recent figure, an emerging topic, or tied to a specific event or context, there may not be substantial details available in my training data up until October 2023.

Jean-Yves Girard is a prominent French logician and philosopher, known for his significant contributions to the fields of mathematical logic, proof theory, and category theory. Born on July 29, 1939, Girard has developed influential concepts and systems within these disciplines. One of his notable contributions is the development of Linear Logic, which he introduced in the 1980s.

Paul Lorenzen (1915-1994) was a German philosopher and logician, known for his work in the fields of constructivism, logic, and the philosophy of language. He is particularly recognized for his contributions to the development of a type of constructive mathematics and for his role in the creation of the so-called "Collegium Logicum," a group that focused on research in logic and related philosophical issues.

T. M. Scanlon, or Thomas M. Scanlon, is an American philosopher known for his work in moral philosophy and political philosophy. He has made significant contributions to the understanding of moral reasoning, contractualism, and the nature of rights and obligations.

William Alvin Howard was an American mathematician known for his contributions to the field of mathematics, particularly in the areas of algebra and number theory. However, there might be a lack of widely recognized information on him compared to other mathematicians.