fix box_approximation of Intersection with unbounded component

Author: schillic

src/LazyOperations/Intersection.jl

@@ -535,6 +535,18 @@ function ρ(d::AbstractVector, cap::Intersection{N,S1,S2};
     return ρ(d, HPolyhedron([constraints_list(cap.X); constraints_list(cap.Y)]))
 end
 
+function _low(cap::Intersection{N}, i::Int) where {N}
+    n = dim(cap)
+    d = SingleEntryVector(i, n, -one(N))
+    return -ρ(d, cap; algorithm="simple")
+end
+
+function _high(cap::Intersection{N}, i::Int) where {N}
+    n = dim(cap)
+    d = SingleEntryVector(i, n, one(N))
+    return ρ(d, cap; algorithm="simple")
+end
+
 """
     isbounded(cap::Intersection)