View source for Visibility From Infinity

{{DISPLAYTITLE:Visibility From Infinity (Geometric Visibility Problems)}}
== Description == 

Given a set $S$ of axis-parallel line segments in the plane and one particular horizontal segments $s$, determine whether there is a point on $s$ that can be seen from infinity, that is, whether there exists an infinite ray starting at the point on $s$ that does not intersect any segment.

== Related Problems == 

Related: [[Visibility Between Segments]], [[Visible Triangle]]

== Parameters == 

$n$: number of axis-parallel line segments

== Table of Algorithms == 

Currently no algorithms in our database for the given problem.

== Reductions FROM Problem == 

{| class="wikitable sortable"  style="text-align:center;" width="100%"

! Problem !! Implication !! Year !! Citation !! Reduction

|-

| [[GeomBase]] ||  style="text-align:left;" | if: to-time $N^{2-\epsilon}$ for some $\epsilon > {0}$<br/>then: from-time: $N^{2-\epsilon'}$ for some $\epsilon' > {0}$ || 1995 || https://doi.org/10.1016/0925-7721(95)00022-2 || [[Reduction from GeomBase to Visibility From Infinity|link]]
|-
|}