Symmetric powers #
This file defines symmetric powers of a type. The nth symmetric power consists of homogeneous n-tuples modulo permutations by the symmetric group.
The special case of 2-tuples is called the symmetric square, which is
addressed in more detail in Data.Sym.Sym2
.
TODO: This was created as supporting material for Sym2
; it
needs a fleshed-out interface.
Tags #
symmetric powers
The nth symmetric power is n-tuples up to permutation. We define it
as a subtype of Multiset
since these are well developed in the
library. We also give a definition Sym.sym'
in terms of vectors, and we
show these are equivalent in Sym.symEquivSym'
.
Equations
Instances For
Equations
Equations
This is the quotient map that takes a list of n elements as an n-tuple and produces an nth symmetric power.
Equations
Instances For
This is the quotient map that takes a list of n elements as an n-tuple and produces an nth symmetric power.
Equations
α ∈ s
means that a
appears as one of the factors in s
.
Equations
Equations
Alias of Sym.notMem_nil
.
Note: Sym.map_id
is not simp-normal, as simp ends up unfolding id
with Sym.map_congr
Alias of Sym.count_coe_fill_self_of_notMem
.
Combinatorial equivalences #
Alias of SymOptionSuccEquiv.encode_of_none_notMem
.