Cardinality of Wick contractions #
theorem
WickContraction.wickContraction_card_eq_sum_zero_none_isSome
{n : ℕ}
:
Fintype.card (WickContraction n.succ) = Fintype.card { c : WickContraction n.succ // ¬(c.getDual? 0).isSome = true } + Fintype.card { c : WickContraction n.succ // (c.getDual? 0).isSome = true }
theorem
WickContraction.wickContraction_zero_none_card
{n : ℕ}
:
Fintype.card { c : WickContraction n.succ // ¬(c.getDual? 0).isSome = true } = Fintype.card (WickContraction n)
theorem
WickContraction.finset_succAbove_succ_disjoint
{n : ℕ}
(a : Finset (Fin n))
(i : Fin n.succ)
:
Disjoint (Finset.map (Fin.succEmb (n + 1)) (Finset.map i.succAboveEmb a)) {0, i.succ}
The Wick contraction in WickContraction n.succ.succ
formed by a Wick contraction
WickContraction n
by inserting at the 0
and i.succ
and contracting these two.
Equations
- One or more equations did not get rendered due to their size.
Instances For
@[simp]
theorem
WickContraction.consAddContract_getDual?_zero
{n : ℕ}
(i : Fin n.succ)
(c : WickContraction n)
:
@[simp]
theorem
WickContraction.consAddContract_getDual?_self_succ
{n : ℕ}
(i : Fin n.succ)
(c : WickContraction n)
:
theorem
WickContraction.mem_consAddContract_of_mem_iff
{n : ℕ}
(i : Fin n.succ)
(c : WickContraction n)
(a : Finset (Fin n))
:
theorem
WickContraction.consAddContract_surjective_on_zero_contract
{n : ℕ}
(i : Fin n.succ)
(c : WickContraction n.succ.succ)
(h : (c.getDual? 0).isSome = true)
(h2 : (c.getDual? 0).get h = i.succ)
:
∃ (c' : WickContraction n), consAddContract i c' = c
theorem
WickContraction.consAddContract_bijection
{n : ℕ}
(i : Fin n.succ)
:
Function.Bijective fun (c : WickContraction n) => ⟨consAddContract i c, ⋯⟩
theorem
WickContraction.wickContraction_zero_some_eq_mul
{n : ℕ}
:
Fintype.card { c : WickContraction n.succ.succ // (c.getDual? 0).isSome = true } = (n + 1) * Fintype.card (WickContraction n)
The cardinality of Wick's contractions as a recursive formula. This corresponds to OEIS:A000085.
Equations
Instances For
The number of Wick contractions in WickContraction n
is equal to the terms in
Online Encyclopedia of Integer Sequences (OEIS) A000085. That is:
1, 1, 2, 4, 10, 26, 76, 232, 764, 2620, 9496, ...