ScalingStacks

Remark 1.3 . [04QZ]

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Remark 1.3.

Note that several different functions vv define the same complex Πv\Pi_{v} by the construction of Example 2. Here is the list of ambiguities.

  1. (1)

    Let v′=v+const:A→ℝv^{\prime}=v+\operatorname{const}:A\to\mathbb{R} be a function different with vv by a constant. Then Πv=Πv′\Pi_{v}=\Pi_{v^{\prime}}.

  2. (2)

    Let A′=A+cA^{\prime}=A+c, where c∈ℤn+1c\in\mathbb{Z}^{n+1} and v′:A′→ℝv^{\prime}:A^{\prime}\to\mathbb{R} is defined by v′​(z+c)=v⁡(z)v^{\prime}(z+c)=v(z). Then Πv=Πv′\Pi_{v}=\Pi_{v^{\prime}}.

  3. (3)

    Let A′A^{\prime} be such that its convex hull Δ′\Delta^{\prime} coincides with Δ\Delta, the convex hull of AA. Let v¯\underline{v} (resp. v′¯\underline{v^{\prime}}) be the maximal convex function such that v¯≤v\underline{v}\leq v (resp. v′¯≤v′\underline{v^{\prime}}\leq v^{\prime}). Suppose that v¯=v′¯\underline{v}=\underline{v^{\prime}}. Then Πv=Πv′\Pi_{v}=\Pi_{v^{\prime}}.

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