pith. sign in
theorem

phi_equation

proved
show as:
module
IndisputableMonolith.Foundation.PhiForcing
domain
Foundation
line
43 · github
papers citing
45 papers (below)

plain-language theorem explainer

The golden ratio φ obeys φ² = φ + 1. This identity is referenced by arguments that derive φ from self-similarity on a discrete J-cost ledger and by downstream results on forcing principles and economic inevitability. The proof reduces the claim to real arithmetic by unfolding the explicit definition of φ and closing via field simplification with nlinarith on square-root identities.

Claim. Let $φ = (1 + √5)/2$. Then $φ² = φ + 1$.

background

The PhiForcing module establishes that self-similarity in a discrete ledger equipped with J-cost forces the golden ratio. φ denotes the positive real solution to x² = x + 1, written explicitly as (1 + √5)/2. The upstream Algebra.PhiRing.phi_equation records the identical algebraic identity in a ring setting; the present version re-derives it for direct use in the foundation layer.

proof idea

The tactic sequence unfolds the definition of φ together with squaring, introduces the non-negativity of 5, verifies that the square of its square root recovers 5, applies field simplification, and closes with nlinarith using the square-root identity and non-negativity of squares.

why it matters

This identity supplies the algebraic core of the phi forcing principle, which states that self-similarity on a J-cost ledger forces the scale ratio to φ. It is invoked directly by golden_constraint_unique, phi_forcing_principle, phi_inv, phi_satisfies, economic_inevitability, and StillnessGenerative results. In the Recognition framework it realizes the T6 step fixing φ as the self-similar fixed point, consistent with the eight-tick octave and D = 3.

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