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5 min read
Overflow and Mathint
Overflow and Mathint In CVL, the type represents unbounded integers, unlike Solidity’s fixed-size types such as . It performs arithmetic without overflow or underflow, which allows reasoning based on...
5 min read
Testing msg.sender and msg.value in CVL
Testing msg.sender and msg.value in CVL Introduction In this chapter, we introduce the variable in CVL, which enables us to make rules for functions that depend on , , and other global variables in...
10 min read
Introduction to Formal Verification
Introduction to Formal Verification Formal verification is the process of mathematically proving a program adheres to a specification. This article introduces conceptually how formal verification...
7 min read
Testing Revert Call In Certora
Testing Revert Call In Certora In this chapter, we will learn how to use method tags ( and ) and the special variable in CVL to verify expected reverts in smart contract execution. Setting Up...
5 min read
Biconditional Operator
Biconditional Operator Introduction The biconditional operator enables us to assert if-and-only-if relationships between boolean values. Implication () states that if condition P is satisfied, then Q...
6 min read
Formally Verifying a Counter
Formally Verifying a Counter In the previous chapter, we learned the theoretical side of formal verification, including what it is and how it works. In this module, we’ll move beyond theory and learn...
13 min read
Certora Require, Assert, and Satisfy
Certora Require, Assert, and Satisfy In the previous chapter, we learned that a specification is a piece of code written in CVL that describes the expected behavior of a smart contract. A...
6 min read
Formally Verifying Ownable.sol
Formally Verifying Ownable.sol Ownable is an abstract contract that provides owner-based access control. When inherited, it restricts specific functions to the owner using the modifier. It has three...
7 min read
Understanding the Spec File in Certora CVL
Understanding the Spec File in Certora CVL In the last chapter, we saw that to perform formal verification using Certora Prover, we need to provide the Prover with the following key items: Smart...
6 min read
Formally Verifying Address Balance
Formally Verifying Address Balance In the previous chapter, we covered how to reason about environment-dependent functions in CVL by focusing on in non-payable contexts. In those examples, access...
4 min read
Formally Verifying Nonces.Sol in OpenZeppelin
Formally Verifying Nonces.Sol in OpenZeppelin Nonces, which stands for "number used once" are used in digital signature schemes to prevent replay attacks. For the purposes of this article, we assume...
4 min read
Formally verifying Initializable.sol
Formally verifying Initializable.sol This article describes how Certora formally verified the Initializable.sol OpenZeppelin contract. We assume the reader is already familiar with how this contract...