# Groups Lecture 17

in which we explore conjugacy classes in $S_n$ and $A_n$, and prove that $A_5$ is simple.

# Groups Lecture 14

in which we meet several standard actions and prove Cayley’s Theorem.

# Groups Lecture 13

in which we meet orbits and stabilisers and prove the Orbit-Stabiliser Theorem.

# Groups Lecture 17

in which we explore conjugacy classes in $S_n$ and $A_n$, and prove that $A_5$ is simple.

# Groups Lecture 14

in which we meet orbits and stabilisers and prove the Orbit-Stabiliser Theorem.