A Holomorphic Germ Extending the Isosceles Pedal Reduction of the Jonah Triangle

We construct an explicit holomorphic function Gt(s)G_t(s)Gt(s) that extends the real isosceles reduction of the pedal map associated with the Nagel line. For t=7/10t=7/10t=7/10, we prove via exact rational arithmetic that the Jonah triangle corresponds to a fixed point s∗=2/7s_* = 2/7s∗=2/7 of GtG_tGt with multiplier λ=451/343\lambda = 451/343λ=451/343. Since ∣λ∣>1|\lambda| > 1∣λ∣>1, Koenigs' theorem implies that the dynamics of GtG_tGt is locally holomorphically conjugate to a linear dilation near s∗s_*s∗. This result establishes that the local complex dynamics at the Jonah point is trivial and non-fractal. We explicitly state that GtG_tGt is not extended to a global map on CP1\mathbb{CP}^1CP1, and no claims are made regarding the global structure of its stable manifold or connections to the Riemann Hypothesis. The paper includes full algebraic proofs and exact verification scripts.Keywords: