It is possible to download a piece of software over the internet and then verify its correctness locally using an appropriate trusted proof system. However, on a blockchain like Ethereum, smart contracts cannot be altered once deployed. This guarantee of immutability makes it possible for end users to interact collectively with a 'networked' piece of software, with the same opportunity to verify its correctness. Formal verification of smart contracts on a blockchain therefore offers an unprecedented opportunity for end users to collectively interact with a deployed instance of software that they can verify while not relying on a central authority. All that is required to be trusted beyond the blockchain itself is an appropriate proof system, a component which always needs to be in the trusted computing base, and whose rules and definitions can be public knowledge. DeepSEA (Deep Simulation of Executable Abstractions) could serve as such a proof system.