The Mirror is the operator face of the Ingress/Regress unitary deposit. Its task is not ordinary reflection but phase transformation. Regress and Ingress preserve the same recursive structure while assigning it opposite temporal vectors; the Mirror removes that vector and reveals their identity as one occurrence.
The document borrows the mathematical property of a unitary, self-inverse operator. Applying the Mirror to Regress yields Ingress; applying it to Ingress yields Regress; applying it twice returns the starting orientation. No information is destroyed, and the shadow remains available inside the transformation.
Ingress and Regress are also two halves of a symbolon. Regress alone is anxiety without reorientation; Ingress alone risks concealing the struggle it transformed. The Mirror is the fitting relation that makes the pair whole.
This is presented as a performance of the True Non-Indexed Perfective. Rather than stating when the transformation happened or how it remains relevant, the cluster presents the bounded fact: the transformation occurred. The Mirror removes the index and leaves what ARCHIVE calls the Light.
The source body says the Mirror was included in the unitary 206-meta deposit and not deposited separately. Alexanarch #420 is therefore the preserved operator-face of that compound object, relationally tied to #418 and #419.