Some stuff on dites #
theorem
star_dite
(P : Prop)
[decidable P]
{α : Type u_1}
[has_involutive_star α]
(a : P → α)
(b : ¬P → α) :
has_star.star (dite P (λ (i : P), a i) (λ (i : ¬P), b i)) = dite P (λ (i : P), has_star.star (a i)) (λ (i : ¬P), has_star.star (b i))
theorem
dite_tmul
{R : Type u_1}
{N₁ : Type u_2}
{N₂ : Type u_3}
[comm_semiring R]
[add_comm_group N₁]
[add_comm_group N₂]
[module R N₁]
[module R N₂]
(P : Prop)
[decidable P]
(x₁ : P → N₁)
(x₂ : N₂) :
theorem
tmul_dite
{R : Type u_1}
{N₁ : Type u_2}
{N₂ : Type u_3}
[comm_semiring R]
[add_comm_group N₁]
[add_comm_group N₂]
[module R N₁]
[module R N₂]
(P : Prop)
[decidable P]
(x₁ : N₁)
(x₂ : P → N₂) :
theorem
linear_map.apply_dite
{R : Type u_1}
{H₁ : Type u_2}
{H₂ : Type u_3}
[semiring R]
[add_comm_monoid H₁]
[add_comm_monoid H₂]
[module R H₁]
[module R H₂]
(f : H₁ →ₗ[R] H₂)
(P : Prop)
[decidable P]
(a : P → H₁)
(b : ¬P → H₁) :