mathlib3

5a61ef19 - feat(ring_theory/witt_vector/teichmuller): Teichmuller representatives (#4690)

feat(ring_theory/witt_vector/teichmuller): Teichmuller representatives (#4690) Co-Authored-By: Rob Y. Lewis <rob.y.lewis@gmail.com> Co-authored-by: Vierkantor <vierkantor@vierkantor.com> Co-authored-by: Rob Lewis <Rob.y.lewis@gmail.com> Co-authored-by: Rob Lewis <rob.y.lewis@gmail.com>