Property-based testing is not proof-based, but stochastic; you define the input space for a property fairly well, then the testing framework samples random poin

Property-based testing is not proof-based, but stochastic; you define the input space for a property fairly well, then the testing framework samples random points within that space. They also generally have reducers, which try to create small failing inputs iteratively after finding one failing input. The difference with fuzzing is mostly that fuzzers are largely black box; the input space is left largely undefined (e.g. AFL: bag of bytes), and the property under test is usually "well, uh, does it explode?". I don't think the popular property-based testing frameworks use instrumentation to guide exploration of the input space.