Add vtx_ref_sum,
    node_ref_d0, node_ref_d0_eqF, node_d0_eq, node_ref_d0_node.
Modify node_d0.
Rm useless T_geom_node.

Use abstract scopes in monomial too.

  itemF, insert0F, replace0F, squeezeF.
And also for associated lemmas.

               fun_ext2 and extT (with 0 or 2 arguments).
And use them!
Enjoy the new one-liner proofs... ;)

Add pow_plus, pow_S (poly_Pdk),

Rename P0k_eq -> P0k_full (modified).
Unify proofs of Monom_0k_eq and Monom_d0_eq.
Cosmetics.

Some style unification + cosmetics.
Rename B0k_eq -> Monom_0k_eq,
       Bd0_eq -> Monom_d0_eq,
       Bd1_eq0 -> Monom_d1_eq0,
       Bd1_neq0 -> Monom_d1_neq0,
       Pdk_monotone* -> Pdk_monot*,
       am_Pd1 -> Pd1_am.

Simplify/compact proofs (avoid weird @sum_*).

Mv up section on face unisolvence (before definition of record FE_LagPdk_cur).

Extract Algebra from Algebra_wDep (without deps).
Update imports.

       Subsets/Compl.v -> Subsets/Subsets.v,
       Lebesgue/bochner_integral -> Lebesgue/Bochner.

Try avoiding using Rcomplements from Coquelicot when there are alternatives
  with stdlib + MC, eg:
  Rcomplements.Rdiv_1 -> Reals.RIneq.Rdiv_1_r,
  Rcomplements.Rminus_eq_0 -> Reals.RIneq.Rminus_diag,
  Rcomplements.SSR_minus -> MC.ssrnat.minusE.
LM is temporarily deactivated...

Plus.plus_is_O_stt -> nat_plus_def
Arith_prebase.plus_minus_stt -> nat_add_sub_r
Arith_prebase.lt_S_n -> PeanoNat.lt_S_n
Arith_prebase.lt_not_le_stt -> Nat.nle_gt
Arith_prebase.lt_0_neq_stt -> nat_neq_0_equiv
FEM is (almost) fine with Coq-8.20.

Unify location of doc:
  at the very beginning, right after the banner,
  or at the beginning of sections.

Some cleaning.
Re-optimize imports.

Mv {nat,ord}_compl, Finite_{family,table} from Algebra to Compl.
Smooth imports.

Simplify proofs in geometry.
Tune imports in FEM.

sym_eq, Logic.eq_sym -> eq_sym.

       MultiplicativeGroup -> GroupMult,
       MultiplicativeMonoid -> MonoidMult,
       ComposeMonoid -> MonoidComp.

Rename "eqF" -> "extF".
Add defs brF, nbrF, eqF, neqF.

Finite_table:
Rename "eqT" -> "extT".
Add defs brT, nbrT, eqT, neqT.

Monoid_compl, Ring_compl, ModuleSpace_compl, matrix, AffineSpace, Sub_struct, Finite_dim,
  geometry, big_Rmult, multi_index, poly_Lagrange, P_approx_k, FE_simplex:
Propagate new API (from Finite_family and Finite_table).

P_approx_k:
Remove ordF, ordF_dec (use brF/brF_dec instead).

Add defs multi_fact, multi_kronecker.

poly_Lagrange:
When needed, use multi_kronecker and multi_fact from MultiplicativeMonoid.