**This is a development version of this entry. It might change over time and is not stable. Please refer to release versions for citations.**

### Abstract

Actuarial Mathematics is a theory in applied mathematics, which is
mainly used for determining the prices of insurance products and
evaluating the liability of a company associating with insurance
contracts. It is related to calculus, probability theory and financial
theory, etc. In this entry, I formalize the very basic part of
Actuarial Mathematics in Isabelle/HOL. The first formalization is
about the theory of interest which deals with interest rates, present
value factors, an annuity certain, etc. I have already formalized the
basic part of Actuarial Mathematics in Coq
(https://github.com/Yosuke-Ito-345/Actuary). This entry is currently
the partial translation and a little generalization of the Coq
formalization. The further translation in Isabelle/HOL is now
proceeding.