The signed permutation of a constraint word #
Given a signed permutation γ k for each generator k, a word w has the signed permutation
wordSP γ w, the product of its letters. When γ J = -1 and γ X(z, i) has matrix U z i, the
matrix of the constraint word of c is consMat c = (-1)^{c_J} U^α V^β
(toMatrix_wordSP_consWord): the word is J^{c_J} ∏ X(x, i)^{c_i} ∏ X(y, i)^{c_{ℓ(x)+i}} and
U^α is the same product over Fin Λ, the coefficients beyond ℓ(x) being zero.
The diagonal entries of a signed permutation matrix are 1 at the points it fixes with sign
+, and otherwise -1 or 0 (toMatrix_apply_self_eq_one_iff, re_one_sub_toMatrix_apply_self).
Signed permutations of words #
The signed permutation of a word, the product of its letters, a letter (k, b) acting as
γ k, inverted when b.
Equations
Instances For
Re (1 - M_{jj}) / 2 is 0 where the signed permutation fixes j with sign +, and at
most 1 elsewhere.
The matrix of a constraint word #
The observable U z i, for a natural i, the identity beyond Λ.
Instances For
The matrix of a constraint word is the constraint's matrix, for generators whose signed
permutations have matrices -1 (for J) and the observables (for the variables).