Supremum independence #
In this file, we define supremum independence of indexed sets. An indexed family f : ι → α
is
sup-independent if, for all a
, f a
and the supremum of the rest are disjoint.
Main definitions #
Finset.SupIndep s f
: a family of elementsf
are supremum independent on the finite sets
.sSupIndep s
: a set of elements are supremum independent.iSupIndep f
: a family of elements are supremum independent.
Main statements #
- In a distributive lattice, supremum independence is equivalent to pairwise disjointness:
- Otherwise, supremum independence is stronger than pairwise disjointness:
Implementation notes #
For the finite version, we avoid the "obvious" definition
∀ i ∈ s, Disjoint (f i) ((s.erase i).sup f)
because erase
would require decidable equality on
ι
.
On lattices with a bottom element, via Finset.sup
#
Equations
- Finset.instDecidableSupIndepOfDecidableEq = Finset.decidableForallOfDecidableSubsets
Alias of the forward direction of Finset.supIndep_iff_pairwiseDisjoint
.
Alias of the reverse direction of Finset.supIndep_iff_pairwiseDisjoint
.
Bind operation for SupIndep
.
Bind operation for SupIndep
.
Bind operation for SupIndep
.
On complete lattices via sSup
#
Alias of sSupIndep_empty
.
Alias of sSupIndep.mono
.
If the elements of a set are independent, then any pair within that set is disjoint.
Alias of sSupIndep.pairwiseDisjoint
.
If the elements of a set are independent, then any pair within that set is disjoint.
Alias of sSupIndep_singleton
.
Alias of sSupIndep_pair
.
Alias of sSupIndep.disjoint_sSup
.
If the elements of a set are independent, then any element is disjoint from the sSup
of some
subset of the rest.
An independent indexed family of elements in a complete lattice is one in which every element
is disjoint from the iSup
of the rest.
Example: an indexed family of non-zero elements in a vector space is linearly independent iff the indexed family of subspaces they generate is independent in this sense.
Example: an indexed family of submodules of a module is independent in this sense if and only the natural map from the direct sum of the submodules to the module is injective.
Instances For
Alias of iSupIndep
.
An independent indexed family of elements in a complete lattice is one in which every element
is disjoint from the iSup
of the rest.
Example: an indexed family of non-zero elements in a vector space is linearly independent iff the indexed family of subspaces they generate is independent in this sense.
Example: an indexed family of submodules of a module is independent in this sense if and only the natural map from the direct sum of the submodules to the module is injective.
Equations
Instances For
Alias of sSupIndep_iff
.
Alias of iSupIndep_def
.
Alias of iSupIndep_def'
.
Alias of iSupIndep_def''
.
Alias of iSupIndep_empty
.
Alias of iSupIndep_pempty
.
If the elements of a set are independent, then any pair within that set is disjoint.
Alias of iSupIndep.pairwiseDisjoint
.
If the elements of a set are independent, then any pair within that set is disjoint.
Alias of iSupIndep.mono
.
Composing an independent indexed family with an injective function on the index results in another indepedendent indexed family.
Alias of iSupIndep.comp
.
Composing an independent indexed family with an injective function on the index results in another indepedendent indexed family.
Alias of iSupIndep.comp'
.
Alias of iSupIndep.sSupIndep_range
.
Alias of iSupIndep_ne_bot
.
Alias of iSupIndep.injOn
.
Alias of iSupIndep.injective
.
Alias of iSupIndep_pair
.
Composing an independent indexed family with an order isomorphism on the elements results in another independent indexed family.
Alias of iSupIndep.map_orderIso
.
Composing an independent indexed family with an order isomorphism on the elements results in another independent indexed family.
Alias of iSupIndep_map_orderIso_iff
.
If the elements of a set are independent, then any element is disjoint from the iSup
of some
subset of the rest.
Alias of iSupIndep.disjoint_biSup
.
If the elements of a set are independent, then any element is disjoint from the iSup
of some
subset of the rest.
Alias of iSupIndep.of_coe_Iic_comp
.
Alias of iSupIndep_iff_supIndep
.
Alias of the forward direction of iSupIndep_iff_supIndep
.
Alias of the reverse direction of iSupIndep_iff_supIndep
.
Alias of iSupIndep.supIndep'
.
A variant of CompleteLattice.iSupIndep_iff_supIndep
for Fintype
s.
Alias of iSupIndep_iff_supIndep_univ
.
A variant of CompleteLattice.iSupIndep_iff_supIndep
for Fintype
s.
Alias of the reverse direction of iSupIndep_iff_supIndep_univ
.
A variant of CompleteLattice.iSupIndep_iff_supIndep
for Fintype
s.
Alias of the forward direction of iSupIndep_iff_supIndep_univ
.
A variant of CompleteLattice.iSupIndep_iff_supIndep
for Fintype
s.
Alias of sSupIndep_iff_pairwiseDisjoint
.
Alias of the reverse direction of sSupIndep_iff_pairwiseDisjoint
.
Alias of iSupIndep_iff_pairwiseDisjoint
.