●In Geometry, Surfaces & Topology:
The
of such a
in 3-dimensional Euclidean
: a
or
by
a
, especially a
, about a
which
in the same
but does not
it (e.g. like
doughnut).
A
which is a product of two circles.
A
which is a product of two circles.;{{lb|en|topology|in combination|n-torus|4-torus|etc.}} The product of the
number of circles.