You should take a look at "The Calculus of Constructions" (1988), which is one of the seminal papers that describes the basis for the Coq (now Rocq) theorem prover:
https://www.academia.edu/47789825/The_calculus_of_constructi...Here's a very relevant quote from the introduction:
> "The calculus of constructions is a higher-order formalism for constructive proofs in natural deduction style. Every proof is a lambda-expression, typed with propositions of the underlying logic. By removing types we get a pure lambda-expression, expressing its associated algorithm. Computing this lambda-expression corresponds roughly to cut-elimination. It is our thesis that (as already advocated by Martin-L6f [36]) the Curry-Howard correspondence between propositions and types is a powerful paradigm for computer science. In the case of constructions, we obtain the notion of a very high-level functional programming language, with complex polymorphism well-suited for module specification [8]. The notion of type encompasses the usual notion of data type, but allows as well arbitrarily complex algorithmic specifications. We develop the basic theory of a calculus of constructions, and prove a strong normalization theorem showing that all computations terminate."
In other words, proofs are expressed as typed lambda terms, i.e. "proofs are programs". This is literally what such theorem provers are: examples of the Curry-Howard correspondence in action. If the correspondence didn't exist, none of these tools would exist.
Here are a couple of quotes from one of the Lean papers, "Theorem Proving in Lean", https://leanprover.github.io/theorem_proving_in_lean/theorem... :
> "This is the approach followed in the Calculus of Constructions, and hence in Lean as well. The fact that the rules for implication in a proof system for natural deduction correspond exactly to the rules governing abstraction and application for functions is an instance of the Curry-Howard isomorphism, sometimes known as the propositions-as-types paradigm."
> "The match statement is part of Lean’s function definition system, which provides convenient and expressive ways of defining complex functions. Once again, it is the Curry-Howard isomorphism that allows us to co-opt this mechanism for writing proofs as well."
All of the other theorem provers and proof assistants I mentioned rely on a similar approach.