lean2/hott/cubical/cube.hlean
2017-03-07 22:56:47 -05:00

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/-
Copyright (c) 2015 Floris van Doorn. All rights reserved.
Released under Apache 2.0 license as described in the file LICENSE.
Author: Floris van Doorn, Jakob von Raumer
Cubes
-/
import .square
open equiv is_equiv sigma sigma.ops
namespace eq
inductive cube {A : Type} {a₀₀₀ : A} : Π{a₂₀₀ a₀₂₀ a₂₂₀ a₀₀₂ a₂₀₂ a₀₂₂ a₂₂₂ : A}
{p₁₀₀ : a₀₀₀ = a₂₀₀} {p₀₁₀ : a₀₀₀ = a₀₂₀} {p₀₀₁ : a₀₀₀ = a₀₀₂}
{p₁₂₀ : a₀₂₀ = a₂₂₀} {p₂₁₀ : a₂₀₀ = a₂₂₀} {p₂₀₁ : a₂₀₀ = a₂₀₂}
{p₁₀₂ : a₀₀₂ = a₂₀₂} {p₀₁₂ : a₀₀₂ = a₀₂₂} {p₀₂₁ : a₀₂₀ = a₀₂₂}
{p₁₂₂ : a₀₂₂ = a₂₂₂} {p₂₁₂ : a₂₀₂ = a₂₂₂} {p₂₂₁ : a₂₂₀ = a₂₂₂}
(s₀₁₁ : square p₀₁₀ p₀₁₂ p₀₀₁ p₀₂₁)
(s₂₁₁ : square p₂₁₀ p₂₁₂ p₂₀₁ p₂₂₁)
(s₁₀₁ : square p₁₀₀ p₁₀₂ p₀₀₁ p₂₀₁)
(s₁₂₁ : square p₁₂₀ p₁₂₂ p₀₂₁ p₂₂₁)
(s₁₁₀ : square p₀₁₀ p₂₁₀ p₁₀₀ p₁₂₀)
(s₁₁₂ : square p₀₁₂ p₂₁₂ p₁₀₂ p₁₂₂), Type :=
idc : cube ids ids ids ids ids ids
variables {A B : Type} {a₀₀₀ a₂₀₀ a₀₂₀ a₂₂₀ a₀₀₂ a₂₀₂ a₀₂₂ a₂₂₂ a a' : A}
{p₁₀₀ : a₀₀₀ = a₂₀₀} {p₀₁₀ : a₀₀₀ = a₀₂₀} {p₀₀₁ : a₀₀₀ = a₀₀₂}
{p₁₂₀ : a₀₂₀ = a₂₂₀} {p₂₁₀ : a₂₀₀ = a₂₂₀} {p₂₀₁ : a₂₀₀ = a₂₀₂}
{p₁₀₂ : a₀₀₂ = a₂₀₂} {p₀₁₂ : a₀₀₂ = a₀₂₂} {p₀₂₁ : a₀₂₀ = a₀₂₂}
{p₁₂₂ : a₀₂₂ = a₂₂₂} {p₂₁₂ : a₂₀₂ = a₂₂₂} {p₂₂₁ : a₂₂₀ = a₂₂₂}
{s₀₁₁ : square p₀₁₀ p₀₁₂ p₀₀₁ p₀₂₁}
{s₂₁₁ : square p₂₁₀ p₂₁₂ p₂₀₁ p₂₂₁}
{s₁₀₁ : square p₁₀₀ p₁₀₂ p₀₀₁ p₂₀₁}
{s₁₂₁ : square p₁₂₀ p₁₂₂ p₀₂₁ p₂₂₁}
{s₁₁₀ : square p₀₁₀ p₂₁₀ p₁₀₀ p₁₂₀}
{s₁₁₂ : square p₀₁₂ p₂₁₂ p₁₀₂ p₁₂₂}
{b₁ b₂ b₃ b₄ : B}
(c : cube s₀₁₁ s₂₁₁ s₁₀₁ s₁₂₁ s₁₁₀ s₁₁₂)
definition idc [reducible] [constructor] := @cube.idc
definition idcube [reducible] [constructor] (a : A) := @cube.idc A a
variables (s₁₁₀ s₁₀₁)
definition refl1 : cube s₀₁₁ s₀₁₁ hrfl hrfl vrfl vrfl :=
by induction s₀₁₁; exact idc
definition refl2 : cube hrfl hrfl s₁₀₁ s₁₀₁ hrfl hrfl :=
by induction s₁₀₁; exact idc
definition refl3 : cube vrfl vrfl vrfl vrfl s₁₁₀ s₁₁₀ :=
by induction s₁₁₀; exact idc
variables {s₁₁₀ s₁₀₁}
definition rfl1 : cube s₀₁₁ s₀₁₁ hrfl hrfl vrfl vrfl := !refl1
definition rfl2 : cube hrfl hrfl s₁₀₁ s₁₀₁ hrfl hrfl := !refl2
definition rfl3 : cube vrfl vrfl vrfl vrfl s₁₁₀ s₁₁₀ := !refl3
-- Variables for composition
variables {a₄₀₀ a₄₀₂ a₄₂₀ a₄₂₂ a₀₄₀ a₀₄₂ a₂₄₀ a₂₄₂ a₀₀₄ a₀₂₄ a₂₀₄ a₂₂₄ : A}
{p₃₀₀ : a₂₀₀ = a₄₀₀} {p₃₀₂ : a₂₀₂ = a₄₀₂} {p₃₂₀ : a₂₂₀ = a₄₂₀} {p₃₂₂ : a₂₂₂ = a₄₂₂}
{p₄₀₁ : a₄₀₀ = a₄₀₂} {p₄₁₀ : a₄₀₀ = a₄₂₀} {p₄₁₂ : a₄₀₂ = a₄₂₂} {p₄₂₁ : a₄₂₀ = a₄₂₂}
{p₀₃₀ : a₀₂₀ = a₀₄₀} {p₀₃₂ : a₀₂₂ = a₀₄₂} {p₂₃₀ : a₂₂₀ = a₂₄₀} {p₂₃₂ : a₂₂₂ = a₂₄₂}
{p₀₄₁ : a₀₄₀ = a₀₄₂} {p₁₄₀ : a₀₄₀ = a₂₄₀} {p₁₄₂ : a₀₄₂ = a₂₄₂} {p₂₄₁ : a₂₄₀ = a₂₄₂}
{p₀₀₃ : a₀₀₂ = a₀₀₄} {p₀₂₃ : a₀₂₂ = a₀₂₄} {p₂₀₃ : a₂₀₂ = a₂₀₄} {p₂₂₃ : a₂₂₂ = a₂₂₄}
{p₀₁₄ : a₀₀₄ = a₀₂₄} {p₁₀₄ : a₀₀₄ = a₂₀₄} {p₁₂₄ : a₀₂₄ = a₂₂₄} {p₂₁₄ : a₂₀₄ = a₂₂₄}
{s₃₀₁ : square p₃₀₀ p₃₀₂ p₂₀₁ p₄₀₁} {s₃₁₀ : square p₂₁₀ p₄₁₀ p₃₀₀ p₃₂₀}
{s₃₁₂ : square p₂₁₂ p₄₁₂ p₃₀₂ p₃₂₂} {s₃₂₁ : square p₃₂₀ p₃₂₂ p₂₂₁ p₄₂₁}
{s₄₁₁ : square p₄₁₀ p₄₁₂ p₄₀₁ p₄₂₁}
{s₀₃₁ : square p₀₃₀ p₀₃₂ p₀₂₁ p₀₄₁} {s₁₃₀ : square p₀₃₀ p₂₃₀ p₁₂₀ p₁₄₀}
{s₁₃₂ : square p₀₃₂ p₂₃₂ p₁₂₂ p₁₄₂} {s₂₃₁ : square p₂₃₀ p₂₃₂ p₂₂₁ p₂₄₁}
{s₁₄₁ : square p₁₄₀ p₁₄₂ p₀₄₁ p₂₄₁}
{s₀₁₃ : square p₀₁₂ p₀₁₄ p₀₀₃ p₀₂₃} {s₁₀₃ : square p₁₀₂ p₁₀₄ p₀₀₃ p₂₀₃}
{s₁₂₃ : square p₁₂₂ p₁₂₄ p₀₂₃ p₂₂₃} {s₂₁₃ : square p₂₁₂ p₂₁₄ p₂₀₃ p₂₂₃}
{s₁₁₄ : square p₀₁₄ p₂₁₄ p₁₀₄ p₁₂₄}
(d : cube s₂₁₁ s₄₁₁ s₃₀₁ s₃₂₁ s₃₁₀ s₃₁₂)
(e : cube s₀₃₁ s₂₃₁ s₁₂₁ s₁₄₁ s₁₃₀ s₁₃₂)
(f : cube s₀₁₃ s₂₁₃ s₁₀₃ s₁₂₃ s₁₁₂ s₁₁₄)
/- Composition of Cubes -/
include c d
definition cube_concat1 : cube s₀₁₁ s₄₁₁ (s₁₀₁ ⬝h s₃₀₁) (s₁₂₁ ⬝h s₃₂₁) (s₁₁₀ ⬝v s₃₁₀) (s₁₁₂ ⬝v s₃₁₂) :=
by induction d; exact c
omit d
include e
definition cube_concat2 : cube (s₀₁₁ ⬝h s₀₃₁) (s₂₁₁ ⬝h s₂₃₁) s₁₀₁ s₁₄₁ (s₁₁₀ ⬝h s₁₃₀) (s₁₁₂ ⬝h s₁₃₂) :=
by induction e; exact c
omit e
include f
definition cube_concat3 : cube (s₀₁₁ ⬝v s₀₁₃) (s₂₁₁ ⬝v s₂₁₃) (s₁₀₁ ⬝v s₁₀₃) (s₁₂₁ ⬝v s₁₂₃) s₁₁₀ s₁₁₄ :=
by induction f; exact c
omit f c
definition eq_of_cube (c : cube s₀₁₁ s₂₁₁ s₁₀₁ s₁₂₁ s₁₁₀ s₁₁₂) :
transpose s₁₀₁⁻¹ᵛ ⬝h s₁₁₀ ⬝h transpose s₁₂₁ =
whisker_square (eq_bot_of_square s₀₁₁) (eq_bot_of_square s₂₁₁) idp idp s₁₁₂ :=
by induction c; reflexivity
definition eq_of_deg12_cube {s s' : square p₀₁₀ p₂₁₀ p₁₀₀ p₁₂₀}
(c : cube vrfl vrfl vrfl vrfl s s') : s = s' :=
by induction s; exact eq_of_cube c
definition square_pathover {A B : Type} {a a' : A} {b₁ b₂ b₃ b₄ : A → B}
{f₁ : b₁ ~ b₂} {f₂ : b₃ ~ b₄} {f₃ : b₁ ~ b₃} {f₄ : b₂ ~ b₄} {p : a = a'}
{q : square (f₁ a) (f₂ a) (f₃ a) (f₄ a)}
{r : square (f₁ a') (f₂ a') (f₃ a') (f₄ a')}
(s : cube (natural_square f₁ p) (natural_square f₂ p)
(natural_square f₃ p) (natural_square f₄ p) q r) : q =[p] r :=
by induction p; apply pathover_idp_of_eq; exact eq_of_deg12_cube s
-- a special case where the endpoints do not depend on `p`
definition square_pathover'
{f₁ : A → b₁ = b₂} {f₂ : A → b₃ = b₄} {f₃ : A → b₁ = b₃} {f₄ : A → b₂ = b₄}
{p : a = a'}
{q : square (f₁ a) (f₂ a) (f₃ a) (f₄ a)}
{r : square (f₁ a') (f₂ a') (f₃ a') (f₄ a')}
(s : cube (vdeg_square (ap f₁ p)) (vdeg_square (ap f₂ p))
(vdeg_square (ap f₃ p)) (vdeg_square (ap f₄ p)) q r) : q =[p] r :=
by induction p;apply pathover_idp_of_eq;exact eq_of_deg12_cube s
/- Transporting along a square -/
-- TODO: remove: they are defined again below
definition cube_transport110 {s₁₁₀' : square p₀₁₀ p₂₁₀ p₁₀₀ p₁₂₀}
(p : s₁₁₀ = s₁₁₀') (c : cube s₀₁₁ s₂₁₁ s₁₀₁ s₁₂₁ s₁₁₀ s₁₁₂) :
cube s₀₁₁ s₂₁₁ s₁₀₁ s₁₂₁ s₁₁₀' s₁₁₂ :=
by induction p; exact c
definition cube_transport112 {s₁₁₂' : square p₀₁₂ p₂₁₂ p₁₀₂ p₁₂₂}
(p : s₁₁₂ = s₁₁₂') (c : cube s₀₁₁ s₂₁₁ s₁₀₁ s₁₂₁ s₁₁₀ s₁₁₂) :
cube s₀₁₁ s₂₁₁ s₁₀₁ s₁₂₁ s₁₁₀ s₁₁₂':=
by induction p; exact c
definition cube_transport011 {s₀₁₁' : square p₀₁₀ p₀₁₂ p₀₀₁ p₀₂₁}
(p : s₀₁₁ = s₀₁₁') (c : cube s₀₁₁ s₂₁₁ s₁₀₁ s₁₂₁ s₁₁₀ s₁₁₂) :
cube s₀₁₁' s₂₁₁ s₁₀₁ s₁₂₁ s₁₁₀ s₁₁₂ :=
by induction p; exact c
definition cube_transport211 {s₂₁₁' : square p₂₁₀ p₂₁₂ p₂₀₁ p₂₂₁}
(p : s₂₁₁ = s₂₁₁') (c : cube s₀₁₁ s₂₁₁ s₁₀₁ s₁₂₁ s₁₁₀ s₁₁₂) :
cube s₀₁₁ s₂₁₁' s₁₀₁ s₁₂₁ s₁₁₀ s₁₁₂ :=
by induction p; exact c
definition cube_transport101 {s₁₀₁' : square p₁₀₀ p₁₀₂ p₀₀₁ p₂₀₁}
(p : s₁₀₁ = s₁₀₁') (c : cube s₀₁₁ s₂₁₁ s₁₀₁ s₁₂₁ s₁₁₀ s₁₁₂) :
cube s₀₁₁ s₂₁₁ s₁₀₁' s₁₂₁ s₁₁₀ s₁₁₂ :=
by induction p; exact c
definition cube_transport121 {s₁₂₁' : square p₁₂₀ p₁₂₂ p₀₂₁ p₂₂₁}
(p : s₁₂₁ = s₁₂₁') (c : cube s₀₁₁ s₂₁₁ s₁₀₁ s₁₂₁ s₁₁₀ s₁₁₂) :
cube s₀₁₁ s₂₁₁ s₁₀₁ s₁₂₁' s₁₁₀ s₁₁₂ :=
by induction p; exact c
/- Each equality between squares leads to a cube which is degenerate in one
dimension. -/
definition deg1_cube {s₁₁₀' : square p₀₁₀ p₂₁₀ p₁₀₀ p₁₂₀} (p : s₁₁₀ = s₁₁₀') :
cube s₁₁₀ s₁₁₀' hrfl hrfl vrfl vrfl :=
by induction p; exact rfl1
definition deg2_cube {s₁₁₀' : square p₀₁₀ p₂₁₀ p₁₀₀ p₁₂₀} (p : s₁₁₀ = s₁₁₀') :
cube hrfl hrfl s₁₁₀ s₁₁₀' hrfl hrfl :=
by induction p; exact rfl2
definition deg3_cube {s₁₁₀' : square p₀₁₀ p₂₁₀ p₁₀₀ p₁₂₀} (p : s₁₁₀ = s₁₁₀') :
cube vrfl vrfl vrfl vrfl s₁₁₀ s₁₁₀' :=
by induction p; exact rfl3
/- For each square of parralel equations, there are cubes where the square's
sides appear in a degenerated way and two opposite sides are ids's -/
section
variables {a₀ a₁ : A} {p₀₀ p₀₂ p₂₀ p₂₂ : a₀ = a₁} {s₁₀ : p₀₀ = p₂₀}
{s₁₂ : p₀₂ = p₂₂} {s₀₁ : p₀₀ = p₀₂} {s₂₁ : p₂₀ = p₂₂}
(sq : square s₁₀ s₁₂ s₀₁ s₂₁)
include sq
definition ids3_cube_of_square : cube (hdeg_square s₀₁)
(hdeg_square s₂₁) (hdeg_square s₁₀) (hdeg_square s₁₂) ids ids :=
by induction p₀₀; induction sq; apply idc
definition ids1_cube_of_square : cube ids ids
(vdeg_square s₁₀) (vdeg_square s₁₂) (hdeg_square s₀₁) (hdeg_square s₂₁) :=
by induction p₀₀; induction sq; apply idc
definition ids2_cube_of_square : cube (vdeg_square s₁₀) (vdeg_square s₁₂)
ids ids (vdeg_square s₀₁) (vdeg_square s₂₁) :=
by induction p₀₀; induction sq; apply idc
end
/- Cube fillers -/
section cube_fillers
variables (s₁₁₀ s₁₁₂ s₀₁₁ s₂₁₁ s₁₀₁ s₁₂₁)
definition cube_fill110 : Σ lid, cube s₀₁₁ s₂₁₁ s₁₀₁ s₁₂₁ lid s₁₁₂ :=
begin
induction s₀₁₁, induction s₂₁₁,
let fillsq := square_fill_l (eq_of_vdeg_square s₁₀₁)
(eq_of_hdeg_square s₁₁₂) (eq_of_vdeg_square s₁₂₁),
apply sigma.mk,
apply cube_transport101 (left_inv (vdeg_square_equiv _ _) s₁₀₁),
apply cube_transport112 (left_inv (hdeg_square_equiv _ _) s₁₁₂),
apply cube_transport121 (left_inv (vdeg_square_equiv _ _) s₁₂₁),
apply ids1_cube_of_square, exact fillsq.2
end
definition cube_fill112 : Σ lid, cube s₀₁₁ s₂₁₁ s₁₀₁ s₁₂₁ s₁₁₀ lid :=
begin
induction s₀₁₁, induction s₂₁₁,
let fillsq := square_fill_r (eq_of_vdeg_square s₁₀₁)
(eq_of_hdeg_square s₁₁₀) (eq_of_vdeg_square s₁₂₁),
apply sigma.mk,
apply cube_transport101 (left_inv (vdeg_square_equiv _ _) s₁₀₁),
apply cube_transport110 (left_inv (hdeg_square_equiv _ _) s₁₁₀),
apply cube_transport121 (left_inv (vdeg_square_equiv _ _) s₁₂₁),
apply ids1_cube_of_square, exact fillsq.2,
end
definition cube_fill011 : Σ lid, cube lid s₂₁₁ s₁₀₁ s₁₂₁ s₁₁₀ s₁₁₂ :=
begin
induction s₁₀₁, induction s₁₂₁,
let fillsq := square_fill_t (eq_of_vdeg_square s₁₁₀) (eq_of_vdeg_square s₁₁₂)
(eq_of_vdeg_square s₂₁₁),
apply sigma.mk,
apply cube_transport110 (left_inv (vdeg_square_equiv _ _) s₁₁₀),
apply cube_transport211 (left_inv (vdeg_square_equiv _ _) s₂₁₁),
apply cube_transport112 (left_inv (vdeg_square_equiv _ _) s₁₁₂),
apply ids2_cube_of_square, exact fillsq.2,
end
definition cube_fill211 : Σ lid, cube s₀₁₁ lid s₁₀₁ s₁₂₁ s₁₁₀ s₁₁₂ :=
begin
induction s₁₀₁, induction s₁₂₁,
let fillsq := square_fill_b (eq_of_vdeg_square s₀₁₁) (eq_of_vdeg_square s₁₁₀)
(eq_of_vdeg_square s₁₁₂),
apply sigma.mk,
apply cube_transport011 (left_inv (vdeg_square_equiv _ _) s₀₁₁),
apply cube_transport110 (left_inv (vdeg_square_equiv _ _) s₁₁₀),
apply cube_transport112 (left_inv (vdeg_square_equiv _ _) s₁₁₂),
apply ids2_cube_of_square, exact fillsq.2,
end
definition cube_fill101 : Σ lid, cube s₀₁₁ s₂₁₁ lid s₁₂₁ s₁₁₀ s₁₁₂ :=
begin
induction s₁₁₀, induction s₁₁₂,
let fillsq := square_fill_t (eq_of_hdeg_square s₀₁₁) (eq_of_hdeg_square s₂₁₁)
(eq_of_hdeg_square s₁₂₁),
apply sigma.mk,
apply cube_transport011 (left_inv (hdeg_square_equiv _ _) s₀₁₁),
apply cube_transport211 (left_inv (hdeg_square_equiv _ _) s₂₁₁),
apply cube_transport121 (left_inv (hdeg_square_equiv _ _) s₁₂₁),
apply ids3_cube_of_square, exact fillsq.2,
end
definition cube_fill121 : Σ lid, cube s₀₁₁ s₂₁₁ s₁₀₁ lid s₁₁₀ s₁₁₂ :=
begin
induction s₁₁₀, induction s₁₁₂,
let fillsq := square_fill_b (eq_of_hdeg_square s₁₀₁) (eq_of_hdeg_square s₀₁₁)
(eq_of_hdeg_square s₂₁₁),
apply sigma.mk,
apply cube_transport101 (left_inv (hdeg_square_equiv _ _) s₁₀₁),
apply cube_transport011 (left_inv (hdeg_square_equiv _ _) s₀₁₁),
apply cube_transport211 (left_inv (hdeg_square_equiv _ _) s₂₁₁),
apply ids3_cube_of_square, exact fillsq.2,
end
end cube_fillers
/- Apply a non-dependent function to an entire cube -/
include c
definition apc (f : A → B) :
cube (aps f s₀₁₁) (aps f s₂₁₁) (aps f s₁₀₁) (aps f s₁₂₁) (aps f s₁₁₀) (aps f s₁₁₂) :=
by cases c; exact idc
omit c
/- Transpose a cube (swap dimensions) -/
include c
definition transpose12 : cube s₁₀₁ s₁₂₁ s₀₁₁ s₂₁₁ (transpose s₁₁₀) (transpose s₁₁₂) :=
by cases c; exact idc
definition transpose13 : cube s₁₁₀ s₁₁₂ (transpose s₁₀₁) (transpose s₁₂₁) s₀₁₁ s₂₁₁ :=
by cases c; exact idc
definition transpose23 : cube (transpose s₀₁₁) (transpose s₂₁₁) (transpose s₁₁₀)
(transpose s₁₁₂) (transpose s₁₀₁) (transpose s₁₂₁) :=
by cases c; exact idc
omit c
/- Inverting a cube along one dimension -/
include c
definition cube_inverse1 : cube s₂₁₁ s₀₁₁ s₁₀₁⁻¹ʰ s₁₂₁⁻¹ʰ s₁₁₀⁻¹ᵛ s₁₁₂⁻¹ᵛ :=
by cases c; exact idc
definition cube_inverse2 : cube s₀₁₁⁻¹ʰ s₂₁₁⁻¹ʰ s₁₂₁ s₁₀₁ s₁₁₀⁻¹ʰ s₁₁₂⁻¹ʰ :=
by cases c; exact idc
definition cube_inverse3 : cube s₀₁₁⁻¹ᵛ s₂₁₁⁻¹ᵛ s₁₀₁⁻¹ᵛ s₁₂₁⁻¹ᵛ s₁₁₂ s₁₁₀ :=
by cases c; exact idc
omit c
definition eq_concat1 {s₀₁₁' : square p₀₁₀ p₀₁₂ p₀₀₁ p₀₂₁} (r : s₀₁₁' = s₀₁₁)
(c : cube s₀₁₁ s₂₁₁ s₁₀₁ s₁₂₁ s₁₁₀ s₁₁₂) : cube s₀₁₁' s₂₁₁ s₁₀₁ s₁₂₁ s₁₁₀ s₁₁₂ :=
by induction r; exact c
definition concat1_eq {s₂₁₁' : square p₂₁₀ p₂₁₂ p₂₀₁ p₂₂₁}
(c : cube s₀₁₁ s₂₁₁ s₁₀₁ s₁₂₁ s₁₁₀ s₁₁₂) (r : s₂₁₁ = s₂₁₁')
: cube s₀₁₁ s₂₁₁' s₁₀₁ s₁₂₁ s₁₁₀ s₁₁₂ :=
by induction r; exact c
definition eq_concat2 {s₁₀₁' : square p₁₀₀ p₁₀₂ p₀₀₁ p₂₀₁} (r : s₁₀₁' = s₁₀₁)
(c : cube s₀₁₁ s₂₁₁ s₁₀₁ s₁₂₁ s₁₁₀ s₁₁₂) : cube s₀₁₁ s₂₁₁ s₁₀₁' s₁₂₁ s₁₁₀ s₁₁₂ :=
by induction r; exact c
definition concat2_eq {s₁₂₁' : square p₁₂₀ p₁₂₂ p₀₂₁ p₂₂₁}
(c : cube s₀₁₁ s₂₁₁ s₁₀₁ s₁₂₁ s₁₁₀ s₁₁₂) (r : s₁₂₁ = s₁₂₁')
: cube s₀₁₁ s₂₁₁ s₁₀₁ s₁₂₁' s₁₁₀ s₁₁₂ :=
by induction r; exact c
definition eq_concat3 {s₁₁₀' : square p₀₁₀ p₂₁₀ p₁₀₀ p₁₂₀} (r : s₁₁₀' = s₁₁₀)
(c : cube s₀₁₁ s₂₁₁ s₁₀₁ s₁₂₁ s₁₁₀ s₁₁₂) : cube s₀₁₁ s₂₁₁ s₁₀₁ s₁₂₁ s₁₁₀' s₁₁₂ :=
by induction r; exact c
definition concat3_eq {s₁₁₂' : square p₀₁₂ p₂₁₂ p₁₀₂ p₁₂₂}
(c : cube s₀₁₁ s₂₁₁ s₁₀₁ s₁₂₁ s₁₁₀ s₁₁₂) (r : s₁₁₂ = s₁₁₂')
: cube s₀₁₁ s₂₁₁ s₁₀₁ s₁₂₁ s₁₁₀ s₁₁₂' :=
by induction r; exact c
infix ` ⬝1 `:75 := cube_concat1
infix ` ⬝2 `:75 := cube_concat2
infix ` ⬝3 `:75 := cube_concat3
infixr ` ⬝p1 `:75 := eq_concat1
infixl ` ⬝1p `:75 := concat1_eq
infixr ` ⬝p2 `:75 := eq_concat2
infixl ` ⬝2p `:75 := concat2_eq
infixr ` ⬝p3 `:75 := eq_concat3
infixl ` ⬝3p `:75 := concat3_eq
end eq