SCO60 Group 2 Exposure Limit V2

Implements the Group 2 exposure-limit paragraphs SCO60.116-119 of BCBS d545 (December 2022). The limit applies to the AGGREGATE book: every direct holding (cash and derivatives) and indirect holding (funds, ETF/ETN or similar) is supplied as a position, and per cryptoasset the legs are summed and counted at the HIGHER of the absolute long and short totals rather than a netted figure (SCO60.119). Both comparisons are strict and cross-multiplied over exact integers (exposure*100 against tier1*multiplier), so exactly 1% is not crossed and exactly 2% is not breached (SCO60.117). In the crossed band only the excess over 1% of Tier 1 takes the 1250% Group 2b weight and the Pillar 3 precheck is unaffected; above 2% the whole book takes the weight and the precheck fails (SCO60.118). Capital must be a positive multiple of 100 minor units so the thresholds and the excess are exact; zero, negative, fractional or over-cap capital is a typed refusal in place of any NaN or Infinity verdict. The caller owns the completeness of the book, the delta adjustment of the legs, and the Tier 1 figure; this node classifies no individual asset and applies no infrastructure-risk add-on, which remain the earlier classifier's decisions. No jurisdiction has adopted this standard as of 2026-10-05; national implementation timelines vary and the node never asserts adoption. No formal correctness proof exists for this node yet (compute_proof_ready: deferred); see the proof-status note below the results.