In page 4 at the last line they define it as:
LASER-Ethereum is a symbolic interpreter for Ethereum bytecode.
Given one or more smart contract accounts as input, it returns a set
of abstract program states. A state consists of the set of values
that the virtual machine variables (such as the program counter,
virtual machine stack, and account ...
Both projects are created by the same team, and are used to analyze bytecode and locate weaknesses listed in the SWC registry. There are some notable differences:
Mythril is a free and open-source smart contract security analyzer. It uses symbolic execution to detect a variety of security vulnerabilities. It runs on your local machine.
MythX is a cloud-...