SSReflect

SSReflect (Small Scale Reflection) is a proof methodology and tactic language for the Coq proof assistant, developed by Georges Gonthier as part of the Mathematical Components project. It uses Boolean reflection to bridge the gap between computable boolean predicates and logical propositions, enabling proofs that are both highly automated and intellectually transparent. Unlike traditional Coq tactics that manipulate proof terms directly, SSReflect tactics operate on the goal structure through a small, predictable set of rewriting and simplification steps. This makes SSReflect proofs composable and readable — qualities that have made it the dominant proof style in the MathComp ecosystem and an influence on Lean and other proof assistants.

SSReflect's insistence on small, inspectable proof steps is not conservatism. It is a bet that proof automation should be understandable, not oracular.