🧮 AxiomForge

Prove 2 + 2 = 4 from the axioms. Every move is legal or refused.

Getting ready…

A real case · you decide

Mireya and the obvious

Mireya — a seventeen-year-old in a school maths club

The idea in play: proving a fact for every number at once, from rules, without assuming it.

At maths club a friend laughs: “Everyone knows a + b = b + a. Why would anyone prove it?”

Mireya has the club’s little rule book: zero, “the next number”, and two rules for adding. Nothing else.

Commutativity is not one of the rules. If it is true, it has to follow from them.

How does Mireya answer her friend?

Halfway through, a step in her proof uses “a + b = b + a” itself.

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