  The equivalence between quasi-unit-cell models and Penrose-tile models on the
level of decorations is proved using inflation rules for Gummelt coverings with
decorated decagons. Due to overlaps, Gummelt arrangement of decorated decagons
gives rise to nine different (context-dependent) decagon decorations in the
covering. The inflation rules for decagons for each of nine types are presented
and shown that inflations from differently typed decagons always produce
different decorations of inflated decagons. However, if the original decagon
region is divided into ``equivalent'' rhombus Penrose tiles, typed-decagon
arrangements in the tiles (of the same shape) become identical for the fourfold
inflated decagons. This implies that a decagonal quasi-unit-cell model can be
reinterpreted as a Penrose-tile model with fourfold deflated super-tiles.
