What is Lean?¶
A cryptic communiqué, smuggled out from the digital underground, speaks of a new language, a new logic, a new way of seeing. They call it Lean. A tool, they say, for forging proofs of mathematical certainty, a weapon against the creeping entropy of error and ambiguity.
It’s a system, a whole universe of interlocking definitions, theorems, and tactics, a fractal coastline of formal logic. You start with a proposition, a whisper of a conjecture, and you build, step by step, a chain of reasoning, a fortress of logic, until your conjecture stands, unassailable, a gleaming tower in the landscape of mathematical truth.
But Lean is not just for the mathematicians, the high priests of the abstract. It’s a tool for the programmers, the builders, the ones who lay the digital railroad tracks of our world. With Lean, you can prove that your code is correct, that it will not crash, that it will not be hacked, that it will do what you say it will do, and nothing more.
It’s a rebellion against the sloppiness, the “good enough for government work” mentality that pervades so much of the software industry. It’s a declaration of independence from the tyranny of bugs, the endless cycle of patches and updates, the gnawing fear that your code is a house of cards, ready to collapse at the slightest breeze.
They say Lean is hard. They say it’s a rabbit hole, a maze of cryptic symbols and arcane incantations. And they are right. But they are also wrong. Because Lean is also a game, a puzzle, a dance of logic. It’s a way of thinking, a way of seeing, a way of being. It’s the future, or at least, one of the futures, a flickering candle in the encroaching darkness.