Published online by Cambridge University Press: 20 November 2018
In 2012, Gubeladze (Adv. Math. 2012) introduced the notion of   $k$ -convex-normal polytopes to show that integral polytopes all of whose edges are longer than
 $k$ -convex-normal polytopes to show that integral polytopes all of whose edges are longer than   $4d(d+1)$  have the integer decomposition property. In the first part of this paper we show that for lattice polytopes there is no diòerence between
 $4d(d+1)$  have the integer decomposition property. In the first part of this paper we show that for lattice polytopes there is no diòerence between   $k$ - and
 $k$ - and   $(k+1)$ -convex-normality (for
 $(k+1)$ -convex-normality (for   $k\ge 3$ ) and improve the bound to
 $k\ge 3$ ) and improve the bound to   $2d(d+1)$ . In the second part we extend the definition to pairs of polytopes. Given two rational polytopes
 $2d(d+1)$ . In the second part we extend the definition to pairs of polytopes. Given two rational polytopes   $P$  and
 $P$  and   $\text{Q}$ , where the normal fan of
 $\text{Q}$ , where the normal fan of   $P$  is a refinement of the normal fan of
 $P$  is a refinement of the normal fan of   $\text{Q}$ , if every edge
 $\text{Q}$ , if every edge   ${{e}_{P}}$  of
 ${{e}_{P}}$  of   $P$  is at least
 $P$  is at least   $d$  times as long as the corresponding face (edge or vertex)
 $d$  times as long as the corresponding face (edge or vertex)   ${{e}_{\text{Q}}}$  of
 ${{e}_{\text{Q}}}$  of   $\text{Q}$ , then
 $\text{Q}$ , then   $(P+\text{Q})\cap {{\mathbb{Z}}^{d}}=(P\cap {{\mathbb{Z}}^{d}})+(\text{Q}\cap {{\mathbb{Z}}^{d}})$ .
 $(P+\text{Q})\cap {{\mathbb{Z}}^{d}}=(P\cap {{\mathbb{Z}}^{d}})+(\text{Q}\cap {{\mathbb{Z}}^{d}})$ .