Let L be a polyhedron in an
n-sphere lSn(n ≧ S) that does not separate Sn. A topological invariant of the
position of L in Sn can be introduced as follows: Let l be an integral (n− 2)-cycle on
L. For each nonnegative integer d, the d-th elementary ideal Ed(l) is associated to l
on L in Sn. If l and l′ are homologous on L, then Ed(l) is equal to Ed(l′). Now
the collection of Ed(l) for all possible l is a topological invariant of L in
Sn.
In this paper the following two cases of Ed(l) are considered: (1) l is a l-cycle on a
𝜃-curve L in S3, and (2) l is a 2-cycle on a 2-link L in S4, i.e., the union of two
disjoint 2-spheres in S4, where each of two 2-spheres is trivially imbedded in
S4.
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