diff options
| author | Georges Gonthier | 2019-02-27 19:07:29 +0100 |
|---|---|---|
| committer | Cyril Cohen | 2019-04-01 17:42:28 +0200 |
| commit | c2c3ceae8a2eabed33028bfff306c5664d0b42f2 (patch) | |
| tree | f2ad780c73b919e0d64162ac02ab89918168d73a /mathcomp/solvable/burnside_app.v | |
| parent | cd958350ffb6836a4e9e02716fc19b1a1d1177cd (diff) | |
Making {fun ...} structural and extending it to dependent functions
Construct `finfun_of` directly from a bespoke indexed inductive type,
which both makes it structurally positive (and therefore usable as a
container in an `Inductive` definition), and accommodates naturally
dependent functions.
This is still WIP, because this PR exposed a serious shortcoming of
the Coq unification algorithm’s implantation of Miller patterns. This
bug defeats the inference of `Canonical` structures for `{ffun S -> T}`
when the instances are defined in the dependent case!
This causes unmanageable regressions starting in `matrix.v`, so I
have not been able to check for any impact past that. I’m pushing this
commit so that the Coq issue may be addressed.
Made `fun_of_fin` structurally decreasing: Changed the primitive
accessor of `finfun_of` from `tfgraph` to the `Funclass` coercion
`fun_of_fin`. This will make it possible to define recursive functions
on inductive types built using finite functions. While`tfgraph` is
still useful to transport the tuple canonical structures to
`finfun_of`, it is no longer central to the theory so its role has
been reduced.
Diffstat (limited to 'mathcomp/solvable/burnside_app.v')
| -rw-r--r-- | mathcomp/solvable/burnside_app.v | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/mathcomp/solvable/burnside_app.v b/mathcomp/solvable/burnside_app.v index 10cbbaa..34c1c7c 100644 --- a/mathcomp/solvable/burnside_app.v +++ b/mathcomp/solvable/burnside_app.v @@ -686,10 +686,10 @@ move=> p; rewrite inE. by do ?case/orP; move/eqP=> <- a; rewrite !(permM, permE); case: a; do 6?case. Qed. -Definition sop (p : {perm cube}) : seq cube := val (val (val p)). +Definition sop (p : {perm cube}) : seq cube := fgraph (val p). Lemma sop_inj : injective sop. -Proof. by do 2!apply: (inj_comp val_inj); apply: val_inj. Qed. +Proof. by move=> p1 p2 /val_inj/(can_inj fgraphK)/val_inj. Qed. Definition prod_tuple (t1 t2 : seq cube) := map (fun n : 'I_6 => nth F0 t2 n) t1. @@ -700,7 +700,7 @@ Proof. by move=> x n0; rewrite -pvalE unlock enum_rank_ord (tnth_nth F0). Qed. Lemma prod_t_correct : forall (x y : {perm cube}) (i : cube), (x * y) i = nth F0 (prod_tuple (sop x) (sop y)) i. Proof. -move=> x y i; rewrite permM -!sop_spec (nth_map F0) // size_tuple /=. +move=> x y i; rewrite permM -!sop_spec [RHS](nth_map F0) // size_tuple /=. by rewrite card_ord ltn_ord. Qed. |