Equations for clamp-kernel-v1
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  clamp
    formula:  y_i = min(max(x_i, lo), hi)
    domain:   x ∈ ℝ^n, lo ≤ hi
    codomain: y ∈ [lo, hi]^n
    invariants:
      - lo ≤ y_i ≤ hi for all i
      - clamp(clamp(x)) = clamp(x)
      - x_i ≤ x_j → y_i ≤ y_j

