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In the book Computational Geometry, Algorithms and Applications from de Berg, van Kreveld, Overmars and schwarzkopf, I read the following in chapter 13.3 on Minkowski sums:

Sometimes $ P \oplus(-R(0,0))$ is referred to as the Minkowski difference of $P$ and $R(0,0)$. Since Minkowski differences are defined differently in the mathematics literature we shall avoid this.

Both $P$ and $R(0,0)$ are polygons, that is: a set of points in $\mathbb R^2$.

Beforehand, the following definitions are made:

For two sets $S_{1,2} \subset \mathbb R^2$, the Minkowski sum is defined as:

$$S_1 \oplus S_2 := \{p+q:p\in S_1, q \in S_2\}$$

For the vectors $p=(p_x,p_y)$ and $q=(q_x,q_y)$, the sum is defined as

$$p+q := (p_x+q_x,p_y+q_y)$$

For a point $p=(p_x,p_y)$, it's defined that

$$-p := (-p_x, -p_y)$$

and for a set $S$ it is defined that

$$-S := \{-p : p \in S\}$$

If not by $A \oplus -B$, how else is a Minkowski difference of the two sets defined? In what cases is that difference important?

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1 Answers1

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This is late but maybe helpful, check out the Wiki page. Basically the idea is that (A - B ) + B = A, so we define

$$A - B = \{ c \in V | c + B \subseteq A \} $$

PenasRaul
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