Let \(T\) be a base type theory. We work in the type theory of spaces in \(T\). We define the topos of linear orders \(\mathord {\textnormal {\textsf {LO}}}\) by the following record type.
- -\(\mathord {\textnormal {\textsf {Carrier}}}:\mathcal {E}\)
- -\({\le }:\mathord {\textnormal {\textsf {Carrier}}}\rightarrow \mathord {\textnormal {\textsf {Carrier}}}\rightarrow \Omega \)
- -\(\mathord {\textnormal {\textsf {b}}}:\mathord {\textnormal {\textsf {Carrier}}}\)
- -\(\mathord {\textnormal {\textsf {t}}}:\mathord {\textnormal {\textsf {Carrier}}}\)
- -\(\_:\mathop {\forall }_{x:\mathord {\textnormal {\textsf {Carrier}}}}x\le x\)
- -\(\_:\mathop {\forall }_{x,y,z:\mathord {\textnormal {\textsf {Carrier}}}}x\le y\rightarrow y\le z\rightarrow x\le z\)
- -\(\_:\mathop {\forall }_{x:\mathord {\textnormal {\textsf {Carrier}}}}\mathord {\textnormal {\textsf {IsContr}}}((y:\mathord {\textnormal {\textsf {Carrier}}})\times (x\le y)\times (y\le x))\)
- -\(\_:\mathop {\forall }_{x:\mathord {\textnormal {\textsf {Carrier}}}}\mathord {\textnormal {\textsf {b}}}\le x\)
- -\(\_:\mathop {\forall }_{x:\mathord {\textnormal {\textsf {Carrier}}}}x\le \mathord {\textnormal {\textsf {t}}}\)
- -\(\_:\neg (\mathord {\textnormal {\textsf {b}}}=\mathord {\textnormal {\textsf {t}}})\)
- -\(\_:\mathop {\forall }_{x,y:\mathord {\textnormal {\textsf {Carrier}}}}(x\le y)\lor (y\le x)\)