mathlib

0f1bc68f - feat(ring_theory/witt_vector/structure_polynomial): examples and basic properties (#4467)

feat(ring_theory/witt_vector/structure_polynomial): examples and basic properties (#4467) This is the 4th and final PR in a series on a fundamental theorem about Witt polynomials. Co-Authored-By: Rob Y. Lewis <rob.y.lewis@gmail.com>