feat(field_theory/mv_polynomial): char_p instance (#3491)
feat(field_theory/mv_polynomial): char_p instance (#3491)

Co-authored-by: Johan Commelin <johan@commelin.net>



Co-authored-by: Rob Lewis <597e2d195b18d1f0b2b6530cee088a0ab0ed3ce2@gmail.com>

leanprover-community/mathlib,leanprover-community/mathlib