A subterminal object
in a category
is an object such that, for every
object
, there is at most one morphism
. If
has a terminal object
, then
is subterminal iff the unique morphism
is a monomorphism.
Thus subterminal objects correspond to subobjects of
the terminal object. In a topos,
the subterminal objects form a Heyting algebra.
Subterminal Object
See also
Category, Monomorphism, Subobject, Terminal Object, ToposExplore with Wolfram|Alpha
References
Mac Lane, S. and Moerdijk, I. Sheaves in Geometry and Logic: A First Introduction to Topos Theory. New York: Springer, 1994.Cite this as:
Weisstein, Eric W. "Subterminal Object." From MathWorld--A Wolfram Resource. https://mathworld.wolfram.com/SubterminalObject.html