42 Computer services, namely, providing temporary use of non-downloadable computer software for performing technical mathematical calculations for use in the fields of mathematics, engineering, and science; providing temporary use of non-downloadable computer software to model, simulate, optimize, control, test, and analyze physics-based systems in the fields of multiphysics modeling, simulation, and optimization; providing temporary use of non-downloadable computer software to model, simulate, optimize, control, test, and analyze physics-based systems in the fields of reaction engineering modeling, simulation, and optimization; rental of computer software for technical mathematical calculations for use in the fields of mathematics, engineering, and science; rental of computer software for use in the fields of multiphysics modeling, simulation, and optimization; rental of computer software for use in the fields of reaction engineering modeling, simulation, and optimization; computer programming for others; computer consulting and technical support services, namely, assisting clients in running models and providing analysis of simulation results; computer software consultation; providing maintenance and repair of computer software applications; providing updates to computer software applications; technical support services, namely, troubleshooting in the nature of diagnosing and repairing computer software problems