Simplify the following text for a Grade 12 native English-speaking person.
Original: In that book , Dirac incorporated the previous work of Werner Heisenberg on matrix mechanics and of Erwin SchrÃ dinger on wave mechanics into a single mathematical formalism that associates measurable quantities to operators acting on the Hilbert space of vectors that describe the state of a physical system .
Simplified: Dirac worked out a formulation of quantum mechanics , which includes Erwin SchrÃ dinger 's wave mechanics and Werner Heisenberg 's matrix mechanics in 1926 .