N-ary maps of filter #
This file defines the binary and ternary maps of filters. This is mostly useful to define pointwise operations on filters.
Main declarations #
Filter.map₂
: Binary map of filters.Filter.map₃
: Ternary map of filters.
Notes #
This file is very similar to Data.Set.NAry
, Data.Finset.NAry
and Data.Option.NAry
. Please
keep them in sync.
The image of a binary function m : α → β → γ
as a function Filter α → Filter β → Filter γ
.
Mathematically this should be thought of as the image of the corresponding function α × β → γ
.
Equations
- One or more equations did not get rendered due to their size.
Instances For
The image of a ternary function m : α → β → γ → δ
as a function
Filter α → Filter β → Filter γ → Filter δ
. Mathematically this should be thought of as the image
of the corresponding function α × β × γ → δ
.
Equations
- One or more equations did not get rendered due to their size.
Instances For
Algebraic replacement rules #
A collection of lemmas to transfer associativity, commutativity, distributivity, ... of operations
to the associativity, commutativity, distributivity, ... of Filter.map₂
of those operations.
The proof pattern is map₂_lemma operation_lemma
. For example, map₂_comm mul_comm
proves that
map₂ (*) f g = map₂ (*) g f
in a CommSemigroup
.
Symmetric statement to Filter.map₂_map_left_comm
.
Symmetric statement to Filter.map_map₂_right_comm
.
Symmetric statement to Filter.map_map₂_distrib_left
.
Symmetric statement to Filter.map_map₂_distrib_right
.
The other direction does not hold because of the f
-f
cross terms on the RHS.
The other direction does not hold because of the h
-h
cross terms on the RHS.
Symmetric statement to Filter.map₂_map_left_anticomm
.
Symmetric statement to Filter.map_map₂_right_anticomm
.
Symmetric statement to Filter.map_map₂_antidistrib_left
.
Symmetric statement to Filter.map_map₂_antidistrib_right
.
If a
is a left identity for f : α → β → β
, then pure a
is a left identity for
Filter.map₂ f
.
If b
is a right identity for f : α → β → α
, then pure b
is a right identity for
Filter.map₂ f
.