Reverse mathematics
BRANCH OF MATHEMATICAL LOGIC THAT SEEKS TO DETERMINE WHICH AXIOMS ARE REQUIRED TO PROVE THEOREMS OF MATHEMATICS
Reverse Mathematics; Weak König's lemma; Weak Konig's lemma; Arithmetical transfinite recursion; Constructive reverse mathematics; Bounded reverse mathematics
Reverse mathematics is a program in mathematical logic that seeks to determine which axioms are required to prove theorems of mathematics. Its defining method can briefly be described as "going backwards from the theorems to the axioms", in contrast to the ordinary mathematical practice of deriving theorems from axioms.