<aside> 🧾
Credential: RUB5-PCAN5-20260813 · Status: PASS · Evidence: E0 + E1
</aside>
Let $P_{\mathrm{sym}}$ be the trivial-character projector for the common $S_3$ action and $P_6$ the Casimir spectral projector at eigenvalue 6. Then
$$ P_{\mathrm{can}}=P_6P_{\mathrm{sym}}=P_{\mathrm{sym}}P_6, $$
$$ P_{\mathrm{can}}^2=P_{\mathrm{can}}=P_{\mathrm{can}}^\dagger, \qquad \operatorname{rank}P_{\mathrm{can}}=5. $$
It selects the unique $S_3$-trivial spin-2 copy inside E47:
$$ \mathbb C^{125}\supset E_{47}\supset E_{\mathrm{can}}, \qquad 125\supset47\supset5. $$
4.163×10^-148.778×10^-157.078×10^-16588a0ba2c095da3b3c83bfb1787522006cbe903bc5858947fc578d55d6b62cd2Professor’s Cube Exhibit — Shared-Carrier S₃ Symmetry Bridge
The existing rank-5 projector is now the fixed projector of the positive joint generator
$A_{can}=K^2+11664(I-P_{sym})$.
The machine certificate proves $\ker A_{can}=\operatorname{im}P_{can}$ and the attained identity
$\|(I-A_{can}/99144)^n-P_{can}\|_2=(15/17)^n$.