The 2017-2018 winter term

as of January 8, 2018

January 9, 2018, Bob Paré,

*Introduction to double categories*

**Abstract:**I will define double categories and their morphisms and give some examples. I will speculate on why I think they may be useful.

January 16, 2018, Bob Rosebrugh (Mount Allison),

*Symmetric lenses and cospans*

**Abstract:**A symmetric lens is state synchronization data and synchronization restoration operations between model domains. An asymmetric lens has only one-way data and operations. Some time ago we showed that spans of asymmetric lenses represent symmetric lenses. In the special case that we named (asymmetric) c-lenses the restoration operation satisfies a universal property. We have recently considered cospans of asymmetric lenses. They also generate symmetric lenses and we can now characterize the special case of symmetric lenses which so arise. When the cospan consists of c-lenses then the symmetric lens has a universal property.

(Joint work with Michael Johnson)

January 23, 2018

January 30, 2018, Michael Lambert

February 6, 2018, Frank Fu,

*An introduction to initial algebraic semantics for data types*

February 13, 2018, Marzieh Bayeh,

*Type inference for quantum lambda calculus*

February 20, 2018,

*Study break*

February 27, 2018, Julien Ross,

*Quantum magic games*

March 6, 2018, Evangelia Aleiferi,

*Spans as cartesian double categories*

March 13, 2018, Gabor Lukacs,

*Long colimits of topological algebras*

March 20, 2018, Xiaoning Bian,

*Relations for Clifford+T operators on two qubits*

**Abstract:**We provide a complete set of relations for Clifford+T operators on two qubits.

March 27, 2018, Fahimeh Bayeh

April 3, 2018, Francisco Rios